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Shopfloor programming — a concept supporting skill-based manufacturing
Shopfloor programming- a concept supporting skill-based manufacturing RAINER SCHULTZ-WILD
Abstract: German-speaking countries have a long tradition of skill-based manufacturing. Within the German dual system of vocational training, production workers are provided with a high degree of qualifications, experience, and skills. Nowadays, however, advances in technology and the increasing use of numeric control for machine tools and other types of production machinery are major factors endangering this tradition. It is therefore of particular interest to investigate the extent to which forms of shopfloor programming are applied which can help to stabilize or even increase production workers' skills and qualifications, thus preserving their ability to work autonomously. Keywords: skill-based manufacturing, shopfloorprogramming, NC technology, operator programming, CNC technology, division of labour, skilled workers, semi-skilled~unskilled workers, labour policy
he skilled and experienced lathe operator working from a blueprint and a process plan, manually controlling a complex machine via switches, wheels and levers to gradually create a correctly sized and shaped part, is a thing of the past. Instead, the tricks of the trade are abstracted and condensed into a control program which merely has to be fed into a machine via a suitable form of data transmission so that workpieces of consistently high quality may be produced without any need for workers requiring particular experience or skills. This scenario - either a dream or a nightmare, depending on one's point of view - is still a long way off. Although the continuing development of NC technology, and the fact that microelectronics have become far more efficient while getting cheaper and cheaper, means that the economic threshold at which automatization becomes feasible is constantly being lowered. However, there are a number of reasons why it is still not possible to do without skilled workers in many production processes 1.
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Institut for SozialwissenschaftlicheForschunge. V. - ISF Miinchen, Jakob-Klar-Strasse 9, D 8000 MiJnchen40, Germany
Early predominanceof office-based programming The crucial advantage of NC technology is that the path and switching information required for controlling the machining of a particular part can be laid down and stored separately from the processing cycle in a control program which may then be loaded as often as required for the automatic production of the workpiece concerned. The process of creating these control programs - p r o g r a m m i n g - can be separated from the machining process in terms of time, place and personnel, and can be organized and rationalized according to its own and specific criteria 2. In the early phases of the industrial use of NC technology up to about the mid 1970s it was usual to separate programming and machining activities completely in terms of staff and organization. One reason for this was undoubtedly because NC-technology was predominantly used by large firms which were organized on the basis of a clear division of labour 3'4. Programming was nearly always regarded as a separate process carried out by the process planning department. However, this does not mean that a consistent model of division of labour and work-organization was established once and for all. The very separation of office-based programming and its remoteness from the shopfloor has not proved to be entirely unproblematic. Program errors are often only recognized when a test run is carried out on the machine; optimization of the program to accelerate the machining process requires specific knowledge of the machines concerned. Thus, there needs to be a large degree of coordination and feedback between the shopfloor and the programmers, and this can be complex and time-consuming. It virtually cannot be avoided that shopfloor workers are involved in the programming process - even if their role is only marginal and confined to the correction of errors. The breakthrough of NC technology into more widespread use in industry only occurred in the mid 1970s at about the same time as 'conventional'
0951-5240/93/010036-08 © 1993 Butterworth-Heinemann Ltd Computer Integrated Manufacturing Systems
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hard-wired NC controls were replaced by Computer Numeric Control (CNC) systems using programmable memories. By 1979, about nine out of ten NC machines produced in the Federal Republic of Germany were equipped with C N C 4.
Scope for new approaches to work organization The acceleration which took place in the spread of NC technology, together with the increased scope for programming and data storage which CNC machines offered, gave a new impetus to discussions about work organization and the deployment of personnel in this field. CNC technology created scope for new approaches to work organization. As Hirsch-Kreinsen describes 5, alternative approaches oriented more towards the shopfloor and based on a less strict division of labour appeared, contrasting with the centralist rationalization strategies based on office-programming in the process planning department and a relatively strict division of labour between planning, conception and scheduling on the one hand and executing actual manufacturing activities in the workshop on the other. Central to this approach to work organization is the concept of shopfloor programming. The term 'shopfloor programming' is not used consistently, but it usually implies that it is not just the correction and optimization of programms which occurs on the shopfloor, but also the writing of the original programme itself. In terms of labour policy it is important to differentiate between programming which takes place at the machine itself, and programming which is carried out in some location near the machines (for example, using programming equipment not linked to the machine). Furthermore, it is necessary to identify whether the programming is carried out by the relevant machine operator or by other members of staff (such as machine setters, first line supervisors or foremen). If the machine operator undertakes the task of programming either on his 'own' machine or after swapping over to a programming station within the workshop, one speaks of operator-programming6. As the use of CNC machines has spread, to what extent has the model of shopfloor programming also become popular? Are firms switching completely or only partially to this form of work organization? What categories of workers are being given the task of machine-tool programming?
About 45% of firms in the investment goods industry have at least one CNC machine in use, and in the mechanical engineering industry the proportion is even higher: 62%. The fact that this technology is relatively 'mature' compared to other CIM components such as CAD or PPC systems is indicated by the relatively small number of firms which in 1986/87 were still only planning to install their first CNC machine. Thus, in a limited sense, a saturation point seems to have been reached: it is unlikely that there will be many more first-time users of NC technology. But this in no way means that the actual number of machines will not continue to grow considerably. Unlike the situation in the 1970s, the use of CNC technology is no longer limited to medium-sized and large firms. Admittedly, there is, in the mid 1980s, still a preponderance of such machines in large rather then smaller firms, but it is a technology which has even spread to firms of very limited size. Thus one in ten companies with fewer than 20 employees uses CNC machines, and in firms with between 20 and 50 employees this figure is approximately one in three. In the case of those with over 100 employees there are CNC machines in over 60% of companies in the investment goods industry, and in mechanical engineering they are found in two-thirds of firms with between 50 and 100 on the payroll (see Figure 1). Of course, in the smaller firms only a few machines are used, whereas the medium- to large-sized firms use more. Thus about nine out of ten companies with fewer than 100 employees have at most five CNC machines, whereas eight out of ten large firms (with at least 1000 employees) have six or more CNC machines. These facts are of some significance for questions regarding the organization of NC work.
Increasing diffusion of shopfloor programming By the late 1980s, shopfloor programming was clearly no longer a rarity. The results of our survey of firms in 1986/87 show that over 70% of firms in the investment goods industry which u s e d CNC machines were producing programmes in the job shops themselves. Shopfloor programming is particularly common in the electrical engineering industry (82%); mechanical engineering and other investment goods industries, including the automobile industry, have average figures (70%), while the steel and light-metal industries have
Extensive spread of CNC technology in the mid 1980s Excluding office and administrative systems, CNC machines are the most common type of computer technology or individual CIM components to be found in the investment goods industry in the Federal Republic of Germany.* CNC machines are, for example, to be found in many more firms than the industrial robots which are so often the subject of discussion.
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* See Schultz-Wild et al. 7. The following statements are based on 1096 questionnaires filled out by West German companies in the capital goods industry. The results of the questionnaires were weighted by size of company and industry branch according to their proportion of employment in the West German investment goods industry. The survey, carried out by ISF Munich, occurred in the context of the RKW-Project A 161, and was conducted during the autumn and winter of 1986/87. Besides the author, members of the project were Christoph Nuber, Frank Rehberg, and Klaus Schmierl. For more details of the survey findings see Schultz-Wild et al. 7 and Hirsch-Kreinsen et al. 8.
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Shopfloor programming - a concept supporting skill-based manufacturing I00 90
80 70 60 50 40 30 20 IO
~0 I000 + O0 -999 )-499 199
Mechanical engineering
Electrical/ electronics
Iron/steel/ metal goods
Steel/ light metal
~,e,~'x .,,o"~ d,°q
ot'
/
Other Total Investment goods industry
Figure 1. Use of CNC machines in companies of different sections and sizes (West German investment goods industry, N = 1,096) ing to the survey of 1986/87, since the mid 1970s shopfloor programming has spread faster than the rate of new entries into the world of CNC technology (see Figure 2). Clearly, what has happened is that since the end of the 1970s and the beginning of the 1980s, many firms which had been using CNC (or just NC) technology for some time have introduced shopfloor programming into their production processes. The fact that the large majority of firms using CNC technology now operate shopfloor programming does not, however, mean that programming is in general a part of the tasks of machine operators, which in turn would mean better conditions for the long-term employment of skilled production workers:
figures of two-thirds and the metal goods industry over 50%. In particular, small firms frequently produce CNC programs on the shopfloor, but about two-thirds of large firms (with over 1000 employees) also use this form of work organization (see Table 1). Clearly, shopfloor programming has gained in attractiveness, and is more common than it used to be. This is partly due to the fact that this form of programming is particularly inviting for firms which are just becoming involved in CNC technology. The cost of setting up office programming is relatively high, and is often perceived as not being worthwhile if only one or two machines are involved which could also be programmed in the workshop itself. However, accord-
Table 1. Shopfloor programming according to industrial sectors and company size (% of companies with CNC-machine tools). West German Investment Goods Industry (= IGI) (N = 490) weighted
Company size (number of employees) -49
50-99
100-199
200-499
500-999
1000+
All companies
Mechanical engineering Electrical/electronics Iron, steel, metal goods Steel, light metal, etc. Other IGI-sectors
80.8 75.0 50.0 81.8 80.6
76.0 100.0 71.4 33.3 66.7
65.1 76.9 50.0 57.1 44.4
64.7 76.9 55.6 100.0 76.5
69.2 100.0 100.0 100.0 71.4
66.7 66.7 0.0 100.0 70.0
71.2 81.9 58.2 66.7 71.8
Total
77.3
74.7
60.3
68.0
79.4
67.7
71.2
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Computer Integrated Manufacturing Systems
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Shopfloor programming alongside established office programming - a frequent scenario
45
According to the 1986/87 survey, nine out of ten of the firms using shopfloor programming do so for normal manufacturing orders, while only a few companies limit its use to exceptional cases, for certain rare or unusual orders, etc. This means that in far more than half the firms with CNC technology, shopfloor programming is part of the normal manufacturing process. However, in only six out of ten firms does programming take place entirely on the shopfloor; otherwise, shopfloor programming, though it goes beyond mere program optimization, is often restricted to certain sections of the programming process only. Thus in many firms which operate with a model of shopfloor programming, it is in fact only part of the programming work which is carried out in this way. On average, in the investment goods industry it is only in about half of the firms that programming takes place exclusively on the shopfloor. In a fifth of firms, 50-100% of programming work takes place on the shopfloor, and in about one third it is less than half the programming jobs (see Figure 3). Particularly in medium-sized and large firms, officebased programming seems to play an important role, even in cases where the principle of shopfloor programming has been introduced. The reason for this, apart from the fact that such firms usually operate with forms of management and work-organization involving a distinct division of labour, lies in the fact that they frequently introduced NC technology at an early stage, and office-based programming became established before improvements in control technology in the mid 1970s made shopfloor programming a more attractive
40
55
3O E
o25 E 0
2O
15
IC
1965
197'0
1975 1980 Year of implementation
1985
Figure 2. First implementation of CNC machine tools and shopfloor programming (West German investment goods industry, N = 490). O: CNC machine tools; 7]: shopfloor programming
• first, it is possible for office and shopfloor programming to exist side by side in different forms and to different extents; • second, as mentioned above shopfloor programming is not the same as operator programming; quite the contrary, the task of programming work can be allotted to other workshop personnel. • third, shopfloor programming can be a transitional arrangement which begins to disappear as more CNC machines are introduced into the company concerned. Above all, in the case of the (usually large) firms which introduced NC technology prior to the mid 1970s it is unlikely that with the introduction of shopfloor programming, the programming office which usually existed in these firms was closed down and the entire task of programming transferred to the shopfloor. Depending, among other things, on the design and layout of the machine controls, the complexity of the workpieces and not least on the qualifications of the personnel involved, it is usually only part of the programming which is shifted to the shopfloor, e.g. programmes for pieces of low to medium complexity which are produced on more modern CNC machines.
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I00
/ /
/ ,
90 80
/ / / / /
3
/
/
Z
/
60 50
/
z
/ /
70
7-
//
40
/ / / / / /
•
/
H:
_Z
H H
-.,2
30 20 I0 0
1-49 50-99
100-199 500-999 :>00-499 IO00um. No. of employees
All cam z~nies
Figure 3. Share of shopfloor programming in total of programming work (West German investment goods industry, N = 349). FI: 1-49%: N: 50-99%; []: 100%
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Shopfloor programming - a concept supporting skill-basedmanufacturing proposition. In contrast to this, smaller firms often introduced NC technology/CNC machines at a later date and went straight into shopfloor programming. As a high proportion of the total stock of CNC machines is to be found in larger firms (more than half of the CNC machines covered by the survey were in companies with more than 500 employees), shopfloor programming is still of considerably less significance overall than the figure of 70% for its general distribution might suggest.
Operator programming - only rarely the dominant form of organization With shopfloor programming the function of machine control is shifted much closer to the actual production process, and the area of activity of the machine operators themselves. This can reduce problems of communication and coordination, increase the shopfloor autonomy, and draw the operators more closely into planning and monitoring operations. There are - often depending on the complexity and frequency of the programming tasks, design of control units, etc. - a wide variety of forms of shopfloor programming, not all of which involve the CNC machine operators regularly in programming for new parts 9. According to the 1986/87 survey, only about 40% of the firms have workshop programming carried out exclusively by the machine operators. This includes arrangements where each operator programs 'his own' machine (during or outside machine operation), or situations where programming takes place using programming equipment which is independent of the machine itself, or there is a programming station in the workshop where a group of operators program on a rotation basis. In about 30% of firms, programming work is carried out on the basis of cooperation between machine operators and other shopfloor personnel, such as foremen, and setters. In another 30% of cases, it is exclusively first line management on the shopfloor who carry out these tasks, without significant involvement
Foremen,supervisors, machinesettersin cooperationwit machine \ operators
~
• only in about 12% of firms using CNC technology is shopfloor programming for normal production processes carried out exclusively by machine operators, while it represents at the same time the dominant form of programming (at least 80% of total programming work); • in just under 30% of firms, shopfloor programming predominates, but the writing of programs is carried out by machine operators and other groups of workers in cooperation with or largely by personnel other than the machine operators themselves; • in about 60% of firms, a large proportion or indeed all of their programming (28%) is still conducted away from the shopfloor.
Foremansupervi , sors machinesettersonly
e
r
sony
Figure 4. Manpower use in shopfloor programming (West German investment goods industry, N = 349).
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of the operators. The latter cases presumably include situations where a specialized parts programmer operates in the vicinity of the workshop (see Figure 4). Thus programming is not necessarily always part of the duties of the machine operator, even when the CNC machine is programmed at shopfloor level. All in all, it can be established that, despite the fact that shopfloor programming is used in a large number of firms, programming work has hitherto not always been part of the normal duties of CNC machine operators. A summary of the respective results of the survey carried out on firms in 1986/87 reveals the following (see Figure 5):
Figure 5. Diffusion of shopfloor and operator programming (West German investment goods industry, N = 1,096). [2: companies with use of CNC machines; []: companies with shopfloor programming; r~: companies with dominance of shopfloor programming (share of shopfloor programming at least 80%); I1: companies with dominance of operator programming (shopfloor programming for normal production jobs, exclusively carried out by machine operators)
Computer Integrated Manufacturing Systems
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The separation, in organizational and personnel terms, of programming from machine-operating is no longer as common as it was up to the mid 1970s, but shopfloor or even operator programming have not become the new predominant forms. Thus the danger of skilled production work being eroded still remains. Shopfloor programming and the internal structure of firms
Shopfloor programming, and in particular operator programming, depend on the qualifications of the skilled workers involved. One might thus expect that this approach to programming would be found in situations where it is largely skilled workers who are still used in the production process, and it can therefore be assumed that the workshop is not organized on the basis of a strict division of labour. As we demonstrated elsewhere, the situation in this respect is varied indeed in the different sectors of the investment goods industry in the Federal Republic of Germany 8. Relatively speaking, mechanical engineering firms employ many more skilled workers than large-scale producers, for example in the electrical/ electronic or automobile industries, which mainly employ semi-skilled and unskilled workers. As has already been stated, CNC technology has been used in the mechanical engineering industry in many more firms and for much longer than in other investment goods industries, but the occurrence of shopfloor programming is, for example, more common in the electrical/electronic industry, where it is found in over 80% of firms using CNC machines compared with 70% for mechanical engineering (see Table 1). The possible relationship between the extent of deployment of skilled labour and the organization of programming comes out even more clearly if one categorizes firms according to the structure of qualifications of their blue collar workers; three types of firms can be differentiated: • firms in which skilled workers represent 60% or more of the blue collar workforce; this is the
dominant type (approximately two-thirds) in the mechanical engineering industry; in these firms the proportion of skilled workers is on average about 80%; firms with at least 60% semi-skilled and/or unskilled workers; in mechanical engineering this applies to about one-sixth of firms, and the average proportion of skilled workers in these is about 25%; finally, firms with a mixed structure, i.e. with roughly equal proportions of skilled workers on the one hand and semi-skilled or unskilled workers on the other. However, it is not possible to identify any clear relationship between the extent of the deployment of skilled workers throughout a firm and the organization of programming. Irrespective of the skill structure of the production workers, in each case more than 70% of firms (also) use shopfloor programming. This form of programming is more frequently the dominant form in firms with roughly equal proportions of skilled and semi-skilled/unskilled workers (mixed structure); it is not found so often in the other two categories. Operator programming, on the other hand, is rather more common among the other two categories. However, the differences are relatively slight (see Table 2). Organization of programming would appear to be rather more strongly influenced by factors other than the extent to which skilled workers are deployed throughout the firm as a whole. It would seem reasonable to suppose that, in firms with a relatively high proportion of semi-skilled and unskilled workers, in areas where CNC technology is used - which are in terms of employment relatively marginal to the activities of the firm in general - there are similar forms of production and work organization as in firms with a higher proportion of skilled workers throughout. The significance of when NC or CNC technology was introduced into a firm has already been pointed out. The number of CNC machines and the degree of differentiation of the firm's in-house and work organization probably also play an important role - and these
Table 2. Organization of programming depending on the skill structure of the companies' blue collar workforce, West German investment goods industry (N =927) weighted
Companies with: use of CNC-machines
Skilled worker companies
Mixed structure companies
Semi-skilled worker companies
53.0
52.3
36.3
72.3 40.4 13.3
72.5 43.8 10.0
70.4 38.8 13.2
out of them: - with shopfloor programming - with dominance of shopfloor programming - with dominance of operator programming
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Shopfloor programming - a concept supporting skill-based manufacturing are factors which partly depend on the size of the company. The distribution of shop floor programming in general varies very much according to the size of the firm, although no consistent pattern can be observed (see Table 3). It is a form of organization frequently found in firms with fewer than 100 and ones with between 500 and 1000 employees. But an (almost) linear relationship can be established with regard to the predominance of shopfloor and operator programming and the size of the firm: the smaller the number of employees in a firm, the more these two forms of organization are likely to predominate. Thus in about half the firms with fewer than 100 employees shopfloor programming is the predominant form of organization, whereas this is the case in only about 13% of large companies. In the latter, operator programming is only rarely the most important form of organization" (3%), whereas it prevails in almost one-fifth of smaller firms with between 50 and 100 employees. Despite the fact that shopfloor and, in particular, operator programming relies on the qualifications of skilled workers, it would seem to be other factors, such as the number of CNC machines (which fluctuates according to the size of firm), the age of the machines and the manner in which they are integrated into the production process, which determine the predominance of certain forms of programming, rather than the skills and qualifications of the company's workforce in general.
Long-term prospects Against this background, the question arises as to the stability of these forms of organizing programming which prevailed in the mid- and late 1980s. On the one hand, there is clear evidence that with the anticipated increase in the deployment of CNC machines, the climate seems favourable for a further spreading of shopfloor programming, in as much as the further development of control technology will pre-
serve or even extend the scope for alternative forms of work organization. On the other hand, such a trend could be countered by the creation of new conditions resulting from increasing computerization and computer integration of process planning, production scheduling and production control. Thus computerized programming aids (e.g. interactive graphics and simulations) have hitherto supported forms of programming remote from the actual machines. Automated programming systems, data integration from design to production, and the use of direct numeric control systems (DNC) are all aimed at rationalizing programming work. This means that programming tasks will become less time-consuming and shopfloor programming will lose part of its attraction. At the moment these two contrary trends would seem to be resulting in a consolidation of recent developments. In 1986/87 more than half (52%) of the firms covered by the survey expected that their proportion of shopfloor programming would remain stable, about one-third expected an increase, and 15% a decrease. However, in the longer term the future of shopfloor programming is very much open to speculation. In terms of labour policy, it can be said that shopfloor programming undoubtedly helps to retain levels of skills and qualifications on the shopfloor. Where programming is a normal part of the job of a machine operator, the latter is not only thereby retaining an activity requiring relevant qualifications, but is also less at risk of losing the broader organizational functions related to that activity and the scope for influencing his own work process. However, shopfloor programming can also involve considerable extra stress for the machine operator concerned. Current design concepts of machines and control systems do not necessarily conform to what would be necessary for optimal use of the experience of qualified skilled workers and the creation of a work situation which is as stress-free as possible. On the one hand, the
Table 3. Organization of programming depended on company size. West German investment goods industry (N = 1.096) weighted Company size (no. of employees) -49
50-99
100-199
200-499
500-999
1000+
Companies with: use of CNC-machines
29.9
43.7
60.0
65.2
80.9
88.6
out of them: - with shopfloor programming - with dominance of shopfloor programming - with dominance of operator programming
76.7 50.7 9.3
75.0 51.9 19.4
59.1 34.4 15.0
68.0 30.7 8.0
79.4 26.5 8.8
67.7 12.9 3.0
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Computer Integrated Manufacturing Systems
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possibilities of improvement offered in principle by suitable software and operator ergonomics have not yet caught on everywhere. And on the other hand, NC training is still often based on ideas derived from data-processing logic and computer science 1°' 11 Thus, in the long-term there is no guarantee that shopfloor programming will be stabilized or even expanded in many firms. Neither is it by any means certain that it will have only positive effects on the working situation of skilled machine operators. For this reason, but also with an eye to the many areas of production, assembly and auxiliary facilities which in the near future will manage to operate without CNC machines, it would be wrong for labour policy to overestimate the significance of shopfloor programming for the consolidation of qualifications - both skill-related and social - in the groups of workers concerned. Much of the evidence suggests that a firm's interest in using skilled production workers is not limited to the area of machine control and/or programming. Generally speaking, machine technology is becoming more elaborate and more complicated. Where capitalintensive and complex modern production and control systems are being employed, approaches to work organization are advantageous which are based on the deployment of skilled and qualified workers directly in the production process 12' ~3. A company can reduce the costs of investing in and introducing new technology, increase the technical availability of the systems in the normal production processes, and enhance the flexibility of system utilization if it deploys properly qualified skilled workers who are familiar with the particular machines and processes involved. Comprehensive labour strategies aimed at securing the position of skilled production workers therefore do not only stress the importance of shopfloor programming but, in addition to machine operation and monitoring, also include the functions of production planning and control, tool preparation and management, maintenance and repair, etc. Such approaches must, however, also ensure that the choice of technology, the organization of the work, and the wages paid create, in the long-term, sufficiently attractive working conditions for suitably skilled workers. In many instances, this necessitates the introduction of inovatory work structures based, for example, on concepts such as 'cellular manufacturing', production islands, or 'skill-based group work' with a reduction in hierarchical and functional divisions of labour and a much greater emphasis on a cooperative, integrated approach to work 14. References 1 Schultz.Wild, R 'On the threshold of computerintegrated manufacturing - diffusion trends of CIM
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technologies in West German industries', Comput. Integr. Manuf. Syst., Vol 2 No 4 (November 1989) pp 240-248 2 Sehultz-Wilfl, R and Weltz, F Technischer Wandel und Industriebetrieb. Die Einfiihrung numerisch gesteuerter Werkzeugmaschinen, Athen~ium Verlag Germany (1973) 3 Simon, W 'Voraussetzungen for den wirtschaftklichen Einsatz numerisch gesteuerter Werkzeugmaschinen in der Fertigung', die Technik, Vol 21 No 2 (February 1966) p 74 4 Rempp, H, Boffo, M and Lay, G Wirtschaftliche und soziale Auswirkungen des CNC-Werkzeugmaschineneinsatzes, Studie des Fraunhofer-Instituts fiir Systemtechnik und Innovationforshung, Hektrogr, Bericht, RKW-Bestell Nr. 758, Eschborn (1981) 5 Hirseh-Kreinsen, H The Use of CNC and Alternative Methods of Work Organization, Mimeograph, Munich (1990) 6 Sehulte, A 'Was heiBt "Werkstattprogrammierung"?' Angewandte Arbeitswissenschaft, No 108 (May 1986) pp3-13 7 Sehultz-Wild, R, Nuber, Ch, Rehberg, F and Sehmierl, K An der Schwelle zu CIM - Strategien Verbreitung, Auswirkungen, RKW-Verlag, Eschborn (1989) 8 Hirseh-Kreinsen, H, Sehultz-Wild, R, K6hler, Ch and Behr, M v Einstieg in die rechnerintegrierte Produktion - Alternative Entwicklungspfade der Industriearbeit im Maschinenbau, Campus Verlag, Frankfurt (1990) 9 Nitzsehe, M and Pfennig, V Einsatz yon CNCWerkzeugmaschinen, Organisation - Arbeitsteilung - Qualifikation, RKW-Verlag und Verlag TUV Rheinland, Eschborn/K61n (1988) 10 B6hle, F and Milkau, B Vom Handrad zum Bildschirm. Eine Untersuchung zur sinnlichen Erfahrung im ArbeitsprozeJ3, Campus Verlag, Frankfurt (1988) 11 Rose, H (ed) Programmieren in der Werkstatt, Perspektiven for Facharbeit mit CNC-Maschinen Campus Verlag, Frankfurt (1990) 12 Martin, T, Ulieh, E and Warneeke, H J 'Appropriate automation for flexible manufacturing', Automatica, Vol 26 No 3 (1990) pp611-616 13 Martin, T, Kivinen, J, Rijnsdorp, J E Rodd, M G and Rouse, W B 'Appropriate automation integrating technical, human, organizational, economic, and cultural factors, llth 1FAC World Congress - Automatic Control in the Service of Mankind, Vol 1, Tallinn, Estonia (August 1990) 14 Hirseh-Kreinsen, H and Sehultz-Wiid, R 'Skilled and cooperative production work in computer integrated manufacturing', llth IFAC World Congress - Automatic Control in the Service of Mankind, Vol 12, Tallinn, Estonia (August 1990) pp213-219
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Abstract: German-speaking countries have a long tradition of skill-based manufacturing. Within the German dual system of vocational training, production workers are provided with a high degree of qualifications, experience, and skills. Nowadays, however, advances in technology and the increasing use of numeric control for machine tools and other types of production machinery are major factors endangering this tradition. It is therefore of particular interest to investigate the extent to which forms of shopfloor programming are applied which can help to stabilize or even increase production workers' skills and qualifications, thus preserving their ability to work autonomously. Keywords: skill-based manufacturing, shopfloorprogramming, NC technology, operator programming, CNC technology, division of labour, skilled workers, semi-skilled~unskilled workers, labour policy
he skilled and experienced lathe operator working from a blueprint and a process plan, manually controlling a complex machine via switches, wheels and levers to gradually create a correctly sized and shaped part, is a thing of the past. Instead, the tricks of the trade are abstracted and condensed into a control program which merely has to be fed into a machine via a suitable form of data transmission so that workpieces of consistently high quality may be produced without any need for workers requiring particular experience or skills. This scenario - either a dream or a nightmare, depending on one's point of view - is still a long way off. Although the continuing development of NC technology, and the fact that microelectronics have become far more efficient while getting cheaper and cheaper, means that the economic threshold at which automatization becomes feasible is constantly being lowered. However, there are a number of reasons why it is still not possible to do without skilled workers in many production processes 1.
T
Institut for SozialwissenschaftlicheForschunge. V. - ISF Miinchen, Jakob-Klar-Strasse 9, D 8000 MiJnchen40, Germany
Early predominanceof office-based programming The crucial advantage of NC technology is that the path and switching information required for controlling the machining of a particular part can be laid down and stored separately from the processing cycle in a control program which may then be loaded as often as required for the automatic production of the workpiece concerned. The process of creating these control programs - p r o g r a m m i n g - can be separated from the machining process in terms of time, place and personnel, and can be organized and rationalized according to its own and specific criteria 2. In the early phases of the industrial use of NC technology up to about the mid 1970s it was usual to separate programming and machining activities completely in terms of staff and organization. One reason for this was undoubtedly because NC-technology was predominantly used by large firms which were organized on the basis of a clear division of labour 3'4. Programming was nearly always regarded as a separate process carried out by the process planning department. However, this does not mean that a consistent model of division of labour and work-organization was established once and for all. The very separation of office-based programming and its remoteness from the shopfloor has not proved to be entirely unproblematic. Program errors are often only recognized when a test run is carried out on the machine; optimization of the program to accelerate the machining process requires specific knowledge of the machines concerned. Thus, there needs to be a large degree of coordination and feedback between the shopfloor and the programmers, and this can be complex and time-consuming. It virtually cannot be avoided that shopfloor workers are involved in the programming process - even if their role is only marginal and confined to the correction of errors. The breakthrough of NC technology into more widespread use in industry only occurred in the mid 1970s at about the same time as 'conventional'
0951-5240/93/010036-08 © 1993 Butterworth-Heinemann Ltd Computer Integrated Manufacturing Systems
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hard-wired NC controls were replaced by Computer Numeric Control (CNC) systems using programmable memories. By 1979, about nine out of ten NC machines produced in the Federal Republic of Germany were equipped with C N C 4.
Scope for new approaches to work organization The acceleration which took place in the spread of NC technology, together with the increased scope for programming and data storage which CNC machines offered, gave a new impetus to discussions about work organization and the deployment of personnel in this field. CNC technology created scope for new approaches to work organization. As Hirsch-Kreinsen describes 5, alternative approaches oriented more towards the shopfloor and based on a less strict division of labour appeared, contrasting with the centralist rationalization strategies based on office-programming in the process planning department and a relatively strict division of labour between planning, conception and scheduling on the one hand and executing actual manufacturing activities in the workshop on the other. Central to this approach to work organization is the concept of shopfloor programming. The term 'shopfloor programming' is not used consistently, but it usually implies that it is not just the correction and optimization of programms which occurs on the shopfloor, but also the writing of the original programme itself. In terms of labour policy it is important to differentiate between programming which takes place at the machine itself, and programming which is carried out in some location near the machines (for example, using programming equipment not linked to the machine). Furthermore, it is necessary to identify whether the programming is carried out by the relevant machine operator or by other members of staff (such as machine setters, first line supervisors or foremen). If the machine operator undertakes the task of programming either on his 'own' machine or after swapping over to a programming station within the workshop, one speaks of operator-programming6. As the use of CNC machines has spread, to what extent has the model of shopfloor programming also become popular? Are firms switching completely or only partially to this form of work organization? What categories of workers are being given the task of machine-tool programming?
About 45% of firms in the investment goods industry have at least one CNC machine in use, and in the mechanical engineering industry the proportion is even higher: 62%. The fact that this technology is relatively 'mature' compared to other CIM components such as CAD or PPC systems is indicated by the relatively small number of firms which in 1986/87 were still only planning to install their first CNC machine. Thus, in a limited sense, a saturation point seems to have been reached: it is unlikely that there will be many more first-time users of NC technology. But this in no way means that the actual number of machines will not continue to grow considerably. Unlike the situation in the 1970s, the use of CNC technology is no longer limited to medium-sized and large firms. Admittedly, there is, in the mid 1980s, still a preponderance of such machines in large rather then smaller firms, but it is a technology which has even spread to firms of very limited size. Thus one in ten companies with fewer than 20 employees uses CNC machines, and in firms with between 20 and 50 employees this figure is approximately one in three. In the case of those with over 100 employees there are CNC machines in over 60% of companies in the investment goods industry, and in mechanical engineering they are found in two-thirds of firms with between 50 and 100 on the payroll (see Figure 1). Of course, in the smaller firms only a few machines are used, whereas the medium- to large-sized firms use more. Thus about nine out of ten companies with fewer than 100 employees have at most five CNC machines, whereas eight out of ten large firms (with at least 1000 employees) have six or more CNC machines. These facts are of some significance for questions regarding the organization of NC work.
Increasing diffusion of shopfloor programming By the late 1980s, shopfloor programming was clearly no longer a rarity. The results of our survey of firms in 1986/87 show that over 70% of firms in the investment goods industry which u s e d CNC machines were producing programmes in the job shops themselves. Shopfloor programming is particularly common in the electrical engineering industry (82%); mechanical engineering and other investment goods industries, including the automobile industry, have average figures (70%), while the steel and light-metal industries have
Extensive spread of CNC technology in the mid 1980s Excluding office and administrative systems, CNC machines are the most common type of computer technology or individual CIM components to be found in the investment goods industry in the Federal Republic of Germany.* CNC machines are, for example, to be found in many more firms than the industrial robots which are so often the subject of discussion.
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* See Schultz-Wild et al. 7. The following statements are based on 1096 questionnaires filled out by West German companies in the capital goods industry. The results of the questionnaires were weighted by size of company and industry branch according to their proportion of employment in the West German investment goods industry. The survey, carried out by ISF Munich, occurred in the context of the RKW-Project A 161, and was conducted during the autumn and winter of 1986/87. Besides the author, members of the project were Christoph Nuber, Frank Rehberg, and Klaus Schmierl. For more details of the survey findings see Schultz-Wild et al. 7 and Hirsch-Kreinsen et al. 8.
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Shopfloor programming - a concept supporting skill-based manufacturing I00 90
80 70 60 50 40 30 20 IO
~0 I000 + O0 -999 )-499 199
Mechanical engineering
Electrical/ electronics
Iron/steel/ metal goods
Steel/ light metal
~,e,~'x .,,o"~ d,°q
ot'
/
Other Total Investment goods industry
Figure 1. Use of CNC machines in companies of different sections and sizes (West German investment goods industry, N = 1,096) ing to the survey of 1986/87, since the mid 1970s shopfloor programming has spread faster than the rate of new entries into the world of CNC technology (see Figure 2). Clearly, what has happened is that since the end of the 1970s and the beginning of the 1980s, many firms which had been using CNC (or just NC) technology for some time have introduced shopfloor programming into their production processes. The fact that the large majority of firms using CNC technology now operate shopfloor programming does not, however, mean that programming is in general a part of the tasks of machine operators, which in turn would mean better conditions for the long-term employment of skilled production workers:
figures of two-thirds and the metal goods industry over 50%. In particular, small firms frequently produce CNC programs on the shopfloor, but about two-thirds of large firms (with over 1000 employees) also use this form of work organization (see Table 1). Clearly, shopfloor programming has gained in attractiveness, and is more common than it used to be. This is partly due to the fact that this form of programming is particularly inviting for firms which are just becoming involved in CNC technology. The cost of setting up office programming is relatively high, and is often perceived as not being worthwhile if only one or two machines are involved which could also be programmed in the workshop itself. However, accord-
Table 1. Shopfloor programming according to industrial sectors and company size (% of companies with CNC-machine tools). West German Investment Goods Industry (= IGI) (N = 490) weighted
Company size (number of employees) -49
50-99
100-199
200-499
500-999
1000+
All companies
Mechanical engineering Electrical/electronics Iron, steel, metal goods Steel, light metal, etc. Other IGI-sectors
80.8 75.0 50.0 81.8 80.6
76.0 100.0 71.4 33.3 66.7
65.1 76.9 50.0 57.1 44.4
64.7 76.9 55.6 100.0 76.5
69.2 100.0 100.0 100.0 71.4
66.7 66.7 0.0 100.0 70.0
71.2 81.9 58.2 66.7 71.8
Total
77.3
74.7
60.3
68.0
79.4
67.7
71.2
38
Computer Integrated Manufacturing Systems
R SCHULTZ-WILD 50
Shopfloor programming alongside established office programming - a frequent scenario
45
According to the 1986/87 survey, nine out of ten of the firms using shopfloor programming do so for normal manufacturing orders, while only a few companies limit its use to exceptional cases, for certain rare or unusual orders, etc. This means that in far more than half the firms with CNC technology, shopfloor programming is part of the normal manufacturing process. However, in only six out of ten firms does programming take place entirely on the shopfloor; otherwise, shopfloor programming, though it goes beyond mere program optimization, is often restricted to certain sections of the programming process only. Thus in many firms which operate with a model of shopfloor programming, it is in fact only part of the programming work which is carried out in this way. On average, in the investment goods industry it is only in about half of the firms that programming takes place exclusively on the shopfloor. In a fifth of firms, 50-100% of programming work takes place on the shopfloor, and in about one third it is less than half the programming jobs (see Figure 3). Particularly in medium-sized and large firms, officebased programming seems to play an important role, even in cases where the principle of shopfloor programming has been introduced. The reason for this, apart from the fact that such firms usually operate with forms of management and work-organization involving a distinct division of labour, lies in the fact that they frequently introduced NC technology at an early stage, and office-based programming became established before improvements in control technology in the mid 1970s made shopfloor programming a more attractive
40
55
3O E
o25 E 0
2O
15
IC
1965
197'0
1975 1980 Year of implementation
1985
Figure 2. First implementation of CNC machine tools and shopfloor programming (West German investment goods industry, N = 490). O: CNC machine tools; 7]: shopfloor programming
• first, it is possible for office and shopfloor programming to exist side by side in different forms and to different extents; • second, as mentioned above shopfloor programming is not the same as operator programming; quite the contrary, the task of programming work can be allotted to other workshop personnel. • third, shopfloor programming can be a transitional arrangement which begins to disappear as more CNC machines are introduced into the company concerned. Above all, in the case of the (usually large) firms which introduced NC technology prior to the mid 1970s it is unlikely that with the introduction of shopfloor programming, the programming office which usually existed in these firms was closed down and the entire task of programming transferred to the shopfloor. Depending, among other things, on the design and layout of the machine controls, the complexity of the workpieces and not least on the qualifications of the personnel involved, it is usually only part of the programming which is shifted to the shopfloor, e.g. programmes for pieces of low to medium complexity which are produced on more modern CNC machines.
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I00
/ /
/ ,
90 80
/ / / / /
3
/
/
Z
/
60 50
/
z
/ /
70
7-
//
40
/ / / / / /
•
/
H:
_Z
H H
-.,2
30 20 I0 0
1-49 50-99
100-199 500-999 :>00-499 IO00um. No. of employees
All cam z~nies
Figure 3. Share of shopfloor programming in total of programming work (West German investment goods industry, N = 349). FI: 1-49%: N: 50-99%; []: 100%
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Shopfloor programming - a concept supporting skill-basedmanufacturing proposition. In contrast to this, smaller firms often introduced NC technology/CNC machines at a later date and went straight into shopfloor programming. As a high proportion of the total stock of CNC machines is to be found in larger firms (more than half of the CNC machines covered by the survey were in companies with more than 500 employees), shopfloor programming is still of considerably less significance overall than the figure of 70% for its general distribution might suggest.
Operator programming - only rarely the dominant form of organization With shopfloor programming the function of machine control is shifted much closer to the actual production process, and the area of activity of the machine operators themselves. This can reduce problems of communication and coordination, increase the shopfloor autonomy, and draw the operators more closely into planning and monitoring operations. There are - often depending on the complexity and frequency of the programming tasks, design of control units, etc. - a wide variety of forms of shopfloor programming, not all of which involve the CNC machine operators regularly in programming for new parts 9. According to the 1986/87 survey, only about 40% of the firms have workshop programming carried out exclusively by the machine operators. This includes arrangements where each operator programs 'his own' machine (during or outside machine operation), or situations where programming takes place using programming equipment which is independent of the machine itself, or there is a programming station in the workshop where a group of operators program on a rotation basis. In about 30% of firms, programming work is carried out on the basis of cooperation between machine operators and other shopfloor personnel, such as foremen, and setters. In another 30% of cases, it is exclusively first line management on the shopfloor who carry out these tasks, without significant involvement
Foremen,supervisors, machinesettersin cooperationwit machine \ operators
~
• only in about 12% of firms using CNC technology is shopfloor programming for normal production processes carried out exclusively by machine operators, while it represents at the same time the dominant form of programming (at least 80% of total programming work); • in just under 30% of firms, shopfloor programming predominates, but the writing of programs is carried out by machine operators and other groups of workers in cooperation with or largely by personnel other than the machine operators themselves; • in about 60% of firms, a large proportion or indeed all of their programming (28%) is still conducted away from the shopfloor.
Foremansupervi , sors machinesettersonly
e
r
sony
Figure 4. Manpower use in shopfloor programming (West German investment goods industry, N = 349).
40
of the operators. The latter cases presumably include situations where a specialized parts programmer operates in the vicinity of the workshop (see Figure 4). Thus programming is not necessarily always part of the duties of the machine operator, even when the CNC machine is programmed at shopfloor level. All in all, it can be established that, despite the fact that shopfloor programming is used in a large number of firms, programming work has hitherto not always been part of the normal duties of CNC machine operators. A summary of the respective results of the survey carried out on firms in 1986/87 reveals the following (see Figure 5):
Figure 5. Diffusion of shopfloor and operator programming (West German investment goods industry, N = 1,096). [2: companies with use of CNC machines; []: companies with shopfloor programming; r~: companies with dominance of shopfloor programming (share of shopfloor programming at least 80%); I1: companies with dominance of operator programming (shopfloor programming for normal production jobs, exclusively carried out by machine operators)
Computer Integrated Manufacturing Systems
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The separation, in organizational and personnel terms, of programming from machine-operating is no longer as common as it was up to the mid 1970s, but shopfloor or even operator programming have not become the new predominant forms. Thus the danger of skilled production work being eroded still remains. Shopfloor programming and the internal structure of firms
Shopfloor programming, and in particular operator programming, depend on the qualifications of the skilled workers involved. One might thus expect that this approach to programming would be found in situations where it is largely skilled workers who are still used in the production process, and it can therefore be assumed that the workshop is not organized on the basis of a strict division of labour. As we demonstrated elsewhere, the situation in this respect is varied indeed in the different sectors of the investment goods industry in the Federal Republic of Germany 8. Relatively speaking, mechanical engineering firms employ many more skilled workers than large-scale producers, for example in the electrical/ electronic or automobile industries, which mainly employ semi-skilled and unskilled workers. As has already been stated, CNC technology has been used in the mechanical engineering industry in many more firms and for much longer than in other investment goods industries, but the occurrence of shopfloor programming is, for example, more common in the electrical/electronic industry, where it is found in over 80% of firms using CNC machines compared with 70% for mechanical engineering (see Table 1). The possible relationship between the extent of deployment of skilled labour and the organization of programming comes out even more clearly if one categorizes firms according to the structure of qualifications of their blue collar workers; three types of firms can be differentiated: • firms in which skilled workers represent 60% or more of the blue collar workforce; this is the
dominant type (approximately two-thirds) in the mechanical engineering industry; in these firms the proportion of skilled workers is on average about 80%; firms with at least 60% semi-skilled and/or unskilled workers; in mechanical engineering this applies to about one-sixth of firms, and the average proportion of skilled workers in these is about 25%; finally, firms with a mixed structure, i.e. with roughly equal proportions of skilled workers on the one hand and semi-skilled or unskilled workers on the other. However, it is not possible to identify any clear relationship between the extent of the deployment of skilled workers throughout a firm and the organization of programming. Irrespective of the skill structure of the production workers, in each case more than 70% of firms (also) use shopfloor programming. This form of programming is more frequently the dominant form in firms with roughly equal proportions of skilled and semi-skilled/unskilled workers (mixed structure); it is not found so often in the other two categories. Operator programming, on the other hand, is rather more common among the other two categories. However, the differences are relatively slight (see Table 2). Organization of programming would appear to be rather more strongly influenced by factors other than the extent to which skilled workers are deployed throughout the firm as a whole. It would seem reasonable to suppose that, in firms with a relatively high proportion of semi-skilled and unskilled workers, in areas where CNC technology is used - which are in terms of employment relatively marginal to the activities of the firm in general - there are similar forms of production and work organization as in firms with a higher proportion of skilled workers throughout. The significance of when NC or CNC technology was introduced into a firm has already been pointed out. The number of CNC machines and the degree of differentiation of the firm's in-house and work organization probably also play an important role - and these
Table 2. Organization of programming depending on the skill structure of the companies' blue collar workforce, West German investment goods industry (N =927) weighted
Companies with: use of CNC-machines
Skilled worker companies
Mixed structure companies
Semi-skilled worker companies
53.0
52.3
36.3
72.3 40.4 13.3
72.5 43.8 10.0
70.4 38.8 13.2
out of them: - with shopfloor programming - with dominance of shopfloor programming - with dominance of operator programming
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Shopfloor programming - a concept supporting skill-based manufacturing are factors which partly depend on the size of the company. The distribution of shop floor programming in general varies very much according to the size of the firm, although no consistent pattern can be observed (see Table 3). It is a form of organization frequently found in firms with fewer than 100 and ones with between 500 and 1000 employees. But an (almost) linear relationship can be established with regard to the predominance of shopfloor and operator programming and the size of the firm: the smaller the number of employees in a firm, the more these two forms of organization are likely to predominate. Thus in about half the firms with fewer than 100 employees shopfloor programming is the predominant form of organization, whereas this is the case in only about 13% of large companies. In the latter, operator programming is only rarely the most important form of organization" (3%), whereas it prevails in almost one-fifth of smaller firms with between 50 and 100 employees. Despite the fact that shopfloor and, in particular, operator programming relies on the qualifications of skilled workers, it would seem to be other factors, such as the number of CNC machines (which fluctuates according to the size of firm), the age of the machines and the manner in which they are integrated into the production process, which determine the predominance of certain forms of programming, rather than the skills and qualifications of the company's workforce in general.
Long-term prospects Against this background, the question arises as to the stability of these forms of organizing programming which prevailed in the mid- and late 1980s. On the one hand, there is clear evidence that with the anticipated increase in the deployment of CNC machines, the climate seems favourable for a further spreading of shopfloor programming, in as much as the further development of control technology will pre-
serve or even extend the scope for alternative forms of work organization. On the other hand, such a trend could be countered by the creation of new conditions resulting from increasing computerization and computer integration of process planning, production scheduling and production control. Thus computerized programming aids (e.g. interactive graphics and simulations) have hitherto supported forms of programming remote from the actual machines. Automated programming systems, data integration from design to production, and the use of direct numeric control systems (DNC) are all aimed at rationalizing programming work. This means that programming tasks will become less time-consuming and shopfloor programming will lose part of its attraction. At the moment these two contrary trends would seem to be resulting in a consolidation of recent developments. In 1986/87 more than half (52%) of the firms covered by the survey expected that their proportion of shopfloor programming would remain stable, about one-third expected an increase, and 15% a decrease. However, in the longer term the future of shopfloor programming is very much open to speculation. In terms of labour policy, it can be said that shopfloor programming undoubtedly helps to retain levels of skills and qualifications on the shopfloor. Where programming is a normal part of the job of a machine operator, the latter is not only thereby retaining an activity requiring relevant qualifications, but is also less at risk of losing the broader organizational functions related to that activity and the scope for influencing his own work process. However, shopfloor programming can also involve considerable extra stress for the machine operator concerned. Current design concepts of machines and control systems do not necessarily conform to what would be necessary for optimal use of the experience of qualified skilled workers and the creation of a work situation which is as stress-free as possible. On the one hand, the
Table 3. Organization of programming depended on company size. West German investment goods industry (N = 1.096) weighted Company size (no. of employees) -49
50-99
100-199
200-499
500-999
1000+
Companies with: use of CNC-machines
29.9
43.7
60.0
65.2
80.9
88.6
out of them: - with shopfloor programming - with dominance of shopfloor programming - with dominance of operator programming
76.7 50.7 9.3
75.0 51.9 19.4
59.1 34.4 15.0
68.0 30.7 8.0
79.4 26.5 8.8
67.7 12.9 3.0
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Computer Integrated Manufacturing Systems
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possibilities of improvement offered in principle by suitable software and operator ergonomics have not yet caught on everywhere. And on the other hand, NC training is still often based on ideas derived from data-processing logic and computer science 1°' 11 Thus, in the long-term there is no guarantee that shopfloor programming will be stabilized or even expanded in many firms. Neither is it by any means certain that it will have only positive effects on the working situation of skilled machine operators. For this reason, but also with an eye to the many areas of production, assembly and auxiliary facilities which in the near future will manage to operate without CNC machines, it would be wrong for labour policy to overestimate the significance of shopfloor programming for the consolidation of qualifications - both skill-related and social - in the groups of workers concerned. Much of the evidence suggests that a firm's interest in using skilled production workers is not limited to the area of machine control and/or programming. Generally speaking, machine technology is becoming more elaborate and more complicated. Where capitalintensive and complex modern production and control systems are being employed, approaches to work organization are advantageous which are based on the deployment of skilled and qualified workers directly in the production process 12' ~3. A company can reduce the costs of investing in and introducing new technology, increase the technical availability of the systems in the normal production processes, and enhance the flexibility of system utilization if it deploys properly qualified skilled workers who are familiar with the particular machines and processes involved. Comprehensive labour strategies aimed at securing the position of skilled production workers therefore do not only stress the importance of shopfloor programming but, in addition to machine operation and monitoring, also include the functions of production planning and control, tool preparation and management, maintenance and repair, etc. Such approaches must, however, also ensure that the choice of technology, the organization of the work, and the wages paid create, in the long-term, sufficiently attractive working conditions for suitably skilled workers. In many instances, this necessitates the introduction of inovatory work structures based, for example, on concepts such as 'cellular manufacturing', production islands, or 'skill-based group work' with a reduction in hierarchical and functional divisions of labour and a much greater emphasis on a cooperative, integrated approach to work 14. References 1 Schultz.Wild, R 'On the threshold of computerintegrated manufacturing - diffusion trends of CIM
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technologies in West German industries', Comput. Integr. Manuf. Syst., Vol 2 No 4 (November 1989) pp 240-248 2 Sehultz-Wilfl, R and Weltz, F Technischer Wandel und Industriebetrieb. Die Einfiihrung numerisch gesteuerter Werkzeugmaschinen, Athen~ium Verlag Germany (1973) 3 Simon, W 'Voraussetzungen for den wirtschaftklichen Einsatz numerisch gesteuerter Werkzeugmaschinen in der Fertigung', die Technik, Vol 21 No 2 (February 1966) p 74 4 Rempp, H, Boffo, M and Lay, G Wirtschaftliche und soziale Auswirkungen des CNC-Werkzeugmaschineneinsatzes, Studie des Fraunhofer-Instituts fiir Systemtechnik und Innovationforshung, Hektrogr, Bericht, RKW-Bestell Nr. 758, Eschborn (1981) 5 Hirseh-Kreinsen, H The Use of CNC and Alternative Methods of Work Organization, Mimeograph, Munich (1990) 6 Sehulte, A 'Was heiBt "Werkstattprogrammierung"?' Angewandte Arbeitswissenschaft, No 108 (May 1986) pp3-13 7 Sehultz-Wild, R, Nuber, Ch, Rehberg, F and Sehmierl, K An der Schwelle zu CIM - Strategien Verbreitung, Auswirkungen, RKW-Verlag, Eschborn (1989) 8 Hirseh-Kreinsen, H, Sehultz-Wild, R, K6hler, Ch and Behr, M v Einstieg in die rechnerintegrierte Produktion - Alternative Entwicklungspfade der Industriearbeit im Maschinenbau, Campus Verlag, Frankfurt (1990) 9 Nitzsehe, M and Pfennig, V Einsatz yon CNCWerkzeugmaschinen, Organisation - Arbeitsteilung - Qualifikation, RKW-Verlag und Verlag TUV Rheinland, Eschborn/K61n (1988) 10 B6hle, F and Milkau, B Vom Handrad zum Bildschirm. Eine Untersuchung zur sinnlichen Erfahrung im ArbeitsprozeJ3, Campus Verlag, Frankfurt (1988) 11 Rose, H (ed) Programmieren in der Werkstatt, Perspektiven for Facharbeit mit CNC-Maschinen Campus Verlag, Frankfurt (1990) 12 Martin, T, Ulieh, E and Warneeke, H J 'Appropriate automation for flexible manufacturing', Automatica, Vol 26 No 3 (1990) pp611-616 13 Martin, T, Kivinen, J, Rijnsdorp, J E Rodd, M G and Rouse, W B 'Appropriate automation integrating technical, human, organizational, economic, and cultural factors, llth 1FAC World Congress - Automatic Control in the Service of Mankind, Vol 1, Tallinn, Estonia (August 1990) 14 Hirseh-Kreinsen, H and Sehultz-Wiid, R 'Skilled and cooperative production work in computer integrated manufacturing', llth IFAC World Congress - Automatic Control in the Service of Mankind, Vol 12, Tallinn, Estonia (August 1990) pp213-219
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