Understanding and assessing complexity in cutting tool management

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51st CIRP Conference on Manufacturing Systems

Understanding28th and assessing complexity in cutting tool management CIRP Design Conference, May 2018, Nantes, France a Eva Boschthe *, Joachim Metternich A new methodology to analyze functional andaphysical architecture of of Production for Management, Technology and Machine Tools (PTW),product Otto-Berndt-Str. family 2, 64287 Darmstadt, Germany existingInstitute products an assembly oriented identification * Corresponding author. Tel.: +49-6151-16-20114; fax: +49-6151-16-20087. E-mail address: [email protected] a

Paul Stief *, Jean-Yves Dantan, Alain Etienne, Ali Siadat Abstract École Nationale Supérieure d’Arts et Métiers, Arts et Métiers ParisTech, LCFC EA 4495, 4 Rue Augustin Fresnel, Metz 57078, France high tool availability is usually theE-mail most important goal in tool management. Ensuring that the tools are provided as required frequently *ACorresponding author. Tel.: +33 3 87named 37 54 30; address: [email protected]

results in excessive tool inventories and thus in high capital commitment costs. Modularization is one possibility to reduce the tool inventory by dismantling the entire system in subsystems, so-called modules. The utilization of modules is advantageous for tools if a high tool variety is needed. Since the trend towards a high product variety is continuing, tool variety is increasing as well. Therefore, the modularization of cutting tools is a current topic in research and industry. Advantages such as reduced setup times, the possibility of combining various components and Abstract using them on machines independent of their interface are going along. Although, there are also some disadvantages. One of the main is the increased complexity in the tool cycle, especially thecustomization tool assemblyis process. Even is high optimization Indisadvantages today’s business environment, the trend towards more product variety in and unbroken. Duethough to this there development, the need of potential in managing theproduction complexity, it has not been addressed in research far, butand needs to be families. understood assessed before being able to agile and reconfigurable systems emerged to cope with various so products product Toand design and optimize production manageas it. well Therefore, approaches for understanding and assessing complexity of the assembly process systems as to choose the optimal product matches, productthe analysis methods aretool needed. Indeed, mostofofmodularized the known cutting methodstools aimare to presented in this paper. this context, methods assessing complexity such as the Variant Treelargely and the are number checkedand for analyze a product or one In product family well-known on the physical level. for Different product families, however, may differ inPetri-Net terms of the their suitability for cutting nature of components. Thistool factmanagement. impedes an efficient comparison and choice of appropriate product family combinations for the production system. A new methodology is proposed to analyze existing products in view of their functional and physical architecture. The aim is to cluster © 2018 The Authors. Publishedoriented by Elsevier B.V.families for the optimization of existing assembly lines and the creation of future reconfigurable these products in new assembly product Peer-review underBased responsibility of Flow the scientific committee the 51stof CIRP Conference on Manufacturing assembly systems. on Datum Chain, the physicalofstructure the products is analyzed. FunctionalSystems. subassemblies are identified, and a functional analysis is performed. Moreover, a hybrid functional and physical architecture graph (HyFPAG) is the output which depicts the Keywords:between Tool Variety; Toolfamilies Modularization; Variant Tree; Petri-Net similarity product by providing design support to both, production system planners and product designers. An illustrative example of a nail-clipper is used to explain the proposed methodology. An industrial case study on two product families of steering columns of thyssenkrupp Presta France is then carried out to give a first industrial evaluation of the proposed approach. © 2017 The Authors. Published by Elsevier B.V. 1. Introduction diagrams are considered Peer-review under responsibility of the scientific committee of the 28th CIRP Design Conference 2018. as useful tools for categorizing and

The change from a seller’s a buyer’s market Keywords: Assembly; Design method; to Family identification

leads to an increased product variety [1]. This also increases the challenges for cutting tool management since a higher tool variety and more frequent tool changes are necessary. Tool management is 1.responsible Introduction for managing all activities involved in the handling of tools such as tool storage, tool assembly, tool presetting and Due to the development the domain tool of measuring, tool fastprovision, tool in disassembly, communication and an ongoing trend of digitization and reconditioning and tool disposal [2]. A high tool availability is digitalization, manufacturing are facing usually mentioned as the enterprises most important goalimportant of tool challenges in today’s market environments: a continuing management [3]. For ensuring the desired availability, usually tendency reduction of product in development times and high tooltowards inventories are established industrial operations, shortened lifecycles. In addition, is an increasing leading toproduct high capital commitment costs.there The resulting conflict demand of customization, being at the same time a global of a high tool availability and low tool inventories isinfrequently competition withmost competitors overin the This trend, quoted as the importantallone toolworld. management [3]. which is inducing the development from macro to lead micro Reducing or even solving this conflict will presumably to markets, in diminished lot sizes the dueconflicting to augmenting an overallresults improvement. For optimizing goals, product varieties (high-volume to low-volume production) [1]. the influencing factors have to be known. Cause-and-effect To cope with this augmenting variety as well as to be able to identify possible optimization potentials in the existing 2212-8271 ©system, 2018 The itAuthors. Publishedtobyhave Elsevier B.V. knowledge production is important a precise

visualizing them. Therefore, after this brief introduction (section 1) a cause-and-effect diagram for a low tool availability is introduced and the complexity in cutting tool management is explained (section 2). Approaches for assessing the complexity of products and of processes (section 3) are addressed next. The of the ends product and characteristics manufactured and/or paper withrange a short conclusion (section 4). assembled in this system. In this context, the main challenge in modelling and analysis is nowinnot only tool to cope with single 2. Understanding complexity cutting management products, a limited product range or existing product families, but to be able to analyze andfortolow compare products to define 2.1.also Cause-and-effect diagram tool availability new product families. It can be observed that classical existing product families are in function of clients Exemplarily, theregrouped cause-and-effect diagram for or a features. low tool However, assembly oriented product families are hardly to find. availability is illustrated in Figure 1, summarizing the results of On the product family level, products differ mainly in two a profound literature research. It becomes clear that there are main characteristics: (i) the of components (ii) the various factors leading to anumber low tool availability. and Therefore, type of components (e.g. mechanical, electrical, electronical). several approaches have been identified in the past for Classicalthe methodologies considering mainlyon single improving tool availability by focusing one products or more or solitary, already existing product families analyze the branches of the diagram [4, 5, 6]. One improvement possibility product structure on a physical level (components level) which causes difficulties regarding an efficient definition and comparison of different product families. Addressing this

Peer-review under responsibility of the scientific committee of the 51st CIRP Conference on Manufacturing Systems.

2212-8271©©2017 2018The The Authors. Published by Elsevier 2212-8271 Authors. Published by Elsevier B.V. B.V. Peer-review under responsibility of scientific the scientific committee theCIRP 51stDesign CIRP Conference Conference2018. on Manufacturing Systems. Peer-review under responsibility of the committee of the of 28th 10.1016/j.procir.2018.03.108

Eva Bosch et al. / Procedia CIRP 72 (2018) 1499–1504 Author name / Procedia CIRP 00 (2018) 000–000

1500 2 Unfavourable assignment plan

Disposition

Unfavourable route planning

Low degree of modularization

Short-term rescheduling Shy of tools planned

Degree of disassembly during storage

Unfavourable scheduling strategy

High order commitment of tools

Early inducement of tool preparation

Coordination difficulties between product and tool flow Unsuitable choice of storage location: central storing

Late labelling of „available“

Poor quality of tools chosen

Lack of transparency No data handling/ software

No tool monitoring Deficient working documents Decentral organization Discrepancy of current and target stock

Preparation/ Reconditioning

Data management

Low degree of standardization Low tool availability

Unreliable transportation system

Lack of competence

Consumption higher than planned

Staff shortage

Long reconditioning times

Coordination difficulties between design and production

Long delivery times

Long transportation times Long preparation times

High product variety

High tool variety

Quantity delivered not as planned

Demand-driven disposition

Stockpiling

Incorrect/no tool tracking

Long-term planning

Mid-term planning

Many components/high degree of modularization Processing station occupied

High wear Tool breakage

Usage

Unavailability of additional equipment/devices Required components are still assembled and have to be disassembled Centralized storing

Figure 1: Cause-and-effect diagram for low tool availability

is the modularization of the cutting tools (see upper right branch of the diagram) which also intends to decrease the tool inventory. However, a high modularity increases the complexity of the tool cycle. 2.2. Complexity Even though complexity is frequently addressed in literature, there are many different definitions of the term. In this paper, complexity is, following the definition of Klabunde [7], defined by the characteristics • variety, • connectivity and • dynamic. Variety describes the number and the type of elements, connectivity focuses on the number and type of relations between these elements and dynamic includes the elusiveness and unpredictability of the system behavior over time. The reasons for complexity are • internal as well as • external factors [8], the so-called complexity drivers. External factors cannot or hardly be influenced by the company’s complexity management such as the customer requirements. Internal factors act within the influenceable boundaries such as the intralogistics process. Identifying, analyzing and understanding complexity drivers are the first steps to develop an effective strategy to handle complexity [9, 10]. Meyer [8] and Monostori et al. [11] further distinguish two complexity types:

• The structural (static) complexity is characterized by the variety of the system elements and includes the product, the process and the organizational structure. ElMaraghy et al. [12] add the market complexity. In the following, the product and the process structure are considered. • The functional/operational (dynamic) complexity, which is characterized by the dynamic of the system elements, includes the process variety and the number and density of interfaces. Regarding the manageability, it is distinguished between • preventing, • mastering/managing and • reducing/eliminating complexity [13]. The focus mastering/managing complexity.

in

this

paper

is

on

2.3. Modularization of cutting tools Tools can be classified according to their system complexity and technological complexity, both attributable to the product complexity. Technological complexity is, among others, described by the complexity of the tool geometry and the tool material. The system complexity exemplarily makes a statement about the number and the interchangeability of components [14]. The modularization of cutting tools ensures a high system complexity and avoids a high technological complexity [14]. A modular system consists of several modules respectively components that can be assembled according to the requirements [15]. The modules are usually standardized and the complexity of each single module is relatively low. The



Eva Bosch et al. / Procedia CIRP 72 (2018) 1499–1504 Author name / Procedia CIRP 00 (2018) 000–000

1501 3

modules are connected by standardized interfaces, enabling easy and quick changes of the modules. The interdependency of the modules is relatively weak [16]. Products, processes or the organization can be modularized [17]. In the context of this paper, modularization refers to products, namely the cutting tools. The benefits of modularization include [18] • the quick realization of product changes and updates by changing modules instead of the entire product, • a better variety management due to the high number of variants to be achieved with few modules and • faster product development processes through the decoupling and parallelization of tasks. In the following, it is distinguished between tool components (also referred to as “components”) and the assembled/entire tool. Components are part of a greater whole – in this context the assembled tool – with a specific function or effect [19]. Their function includes cutting, clamping, tightening, positioning and fixating. The assembled tool consists of one or more components, which fulfill the requirements to machine the workpiece and for being clamped in the machine spindle. In this paper, the distinguished components and their descriptions are listed in Table 1.

Figure 2: Interfaces of a cutting tool

• Hollow taper shank (HSK) • Polygonal taper interface with flange contact surface (CCS) • Modular taper interface with ball track system (KMT) Further standardized interfaces, which are considered in more detail in the following, are:

Component

Description

• • • • • • •

Tool holder/ chuck

Tool holders connect the tool to the chucking shank of a machine tool (e.g. tool holder with a hollow taper shank).

In this paper, the influence of the interfaces on the tool cycle are of relevance and will be discussed next.

Table 1: Tool components

Adapter

Adapters are used to match the requirements of the tool holder and the cutting edge holder or the whole tool to the manufacturing process or environment. Therefore, their function can be the reduction, extension or change in diameter.

Cutting edge holder

In some applications, an indexable insert is attached to a cutting edge holder.

Cutting edge

This component inserts into the workpiece and produces the chip. It can either be an indexable insert, which has to be attached to a cutting edge holder/shank, or a solid cutting edge.

2.4. Module interfaces The components explained above have to be connected. It is distinguished between interfaces relating to the external connections and the ones relating to the internal connections (see Figure 2). The focus in this paper is on the latter since they mainly influence the tool cycle respectively the complexity of the tool assembly process. Different connection types are distinguished and some of them are normed in DIN4000-95 [20]. Five of them mainly characterize the external connection between the tool holder/chunk and the chucking shank of a machine tool for rotating tools and are further considered. These are: • Metric/Morse taper shank (MEK/MKG) • Steep taper shank (SK)

Cartridge (KKH) Cutter arbor (FDA) Screw chuck (SAD) Adjustable adaptor (STH) Cylindrical shank (ZYL, ZYV) Chuck adaptor (BFA) Collet Chuck (SZD)

2.5. Influence of the interfaces on the tool cycle Unlike workpieces, tools go through a cycle (see Figure 3) [4]. After being delivered from an external partner or being produced in the internal tooling shop, the tools are usually stored. As soon as they are needed for production, they are taken out of the storage area and prepared according to the requirements. The preparation includes the commissioning of the components, their assembly as well as the presetting and measuring of the entire tool. The tools are transported to the respective machines and used for the production of the workpiece. After usage, the tools are reconditioned, which includes the examination of the state of wear, the disassembly,

Figure 3: Tool cycle (following [4])

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the cleaning and the treatment. The reconditioned tools are stored again until they are needed for production. The elaboration of the stations of the tool cycle depends on the individual components, respectively on the interfaces. This concerns in particular the tool preparation because the interface determines the clamping method. Therefore, the necessary devices for the previously named interfaces are explained in the following. Cartridges (KKH) are used for mounting indexable inserts. For this, usually only a screwdriver is necessary, which is why they can be assembled anywhere. The assembly of a component with a cutter arbor (FDA) involves more components and devices and therefore results in a more complex assembly process. First of all, an assembly trestle for fixating the tool holder is required. After placing the tool holder into the trestle, distance sleeves (if necessary) and the tool, mostly end face mills, are positioned on the tool holder. Finally, a clamping screw is placed on the tool holder and tightened with a corresponding key. Components can also easily be screwed into each other (SAD). For this, no further devices are necessary and the assembly process is independent of the location. Adjustable adaptors (STH) are used for adjusting the length of the entire tool. For this, nuts and the corresponding wrench are needed. Rotating tools usually have a cylindrical shank (ZYL, ZYV). The clamping surface is even or slightly inclined depending on the clamping method. They can exemplarily be clamped with drill chucks, collet chucks, heat shrink tool chucks, hydraulic chucks, Weldon chucks, Whistle-Notch chucks and with chucks working with the Tribos System. These methods are described in more detail in the following paragraphs. A chuck adapter (BFA) connects the machine and the drill chuck holding the drill. The chuck adapter and the drill chuck are usually connected manually. The clamping pressure of the drill chuck is applied by key or by hand without any additional devices [21]. Therefore, it can take place anywhere. Another advantage is the high clamping range of more than 10 mm. However, it is unsuitable for high-precision machining due to its low concentricity of more than 30 µm [21]. In the drill chuck, three clamping jaws fixate the cylindrical shank of the tool. Collet Chucks (SZD) are frequently used for clamping parallel/cylindrical shanks, because they are relatively inexpensive and highly flexible due to a wide range of collet sizes that are easily interchangeable. One of the shortcomings of this method is the poor clamping pressure and tolerances. For clamping the holder, a collet and a nut are required. Additionally, an assembly trestle is necessary to exert sufficient pressure. One of the most precise clamping methods in terms of concentricity is the clamping with a heat shrink tool chuck [22]. Under this method, the tool holder’s shaft is heated by induction. The shaft widens and the tool with the cylindrical shaft can be inserted. By cooling down, the tool is clamped. For this method, a shrink fit machine is required. Another popular method for high precision machining is the clamping with a hydraulic chuck. The tool holder works by using fluid to compress an internal membrane within the holder

body. The hydraulic fluid is compressed by using a T-handle wrench to turn a pressure screw. The fluid spreads equally around the membrane, enabling a uniform pressure distribution. Tools with an inclined clamping surface are clamped by inserting a screw within the holder body until it touches and fixates the tool. The Weldon chuck is used for shanks with a flat according to DIN 1835-B and DIN 6535-HB [23] and the Whistle-Notch chuck is used for cylindrical shanks with an inclined flat (2-3°) according to DIN 1835-E and DIN 6535HE [23]. A wrench is needed for the assembly process. A similar level of precision to that provided by hydraulic chucks is realized with the Tribos System. In the relaxed state, the clamping chuck has a polygonal form. A clamping device is needed to equip and replace the tool. With this device, force is applied to create a circular shape. Table 2 summarizes the explanations regarding the devices and locations for the interfaces. Table 2: Devices and locations Interface

Device

Location

Cartridge

Screwdriver

Variable

Cutter arbor

Assembly trestle

Fix

Distance sleeves Clamping screw Key Screw chuck

-

Variable

Adjustable adaptor

Nut

Variable

Wrench Chuck adapter

-

Variable

Collet chuck

Assembly trestle

Fix

Collet Nut Heat shrink tool chuck

Shrink fit machine

Fix

Hydraulic chuck

Wrench

Variable

Weldon/Whistle-Notch chuck

Wrench

Variable

Tribos System

Clamping device

Fix

If additional, stationary equipment is necessary, the components have to be routed accordingly. The number of assembly stations depends, among others, on the investment costs of the equipment. Since shrink fit machines are rather expensive, they are usually located centrally in the plant. Cheaper is exemplarily using collet chucks and the Tribos System. However, the least expensive solution regarding the additional equipment are – aside from the manual clamping – the clamping methods only requiring a wrench. Independent of the clamping method, most of the assembled tools have to be preset and measured before usage. In some machines, the presetting and measuring process is integrated. In all other cases, a presetting and measuring machine is required, determining the further route of the tool. Since these machines are rather expensive and may need special climate conditions, they are usually located centrally in the plant. For the disassembly process, the same equipment is needed as for the assembly process. Therefore, the tools have to be routed accordingly. Reconditioning is only necessary for the



Eva Bosch et al. / Procedia CIRP 72 (2018) 1499–1504 Author name / Procedia CIRP 00 (2018) 000–000

wear parts, i.e. for the cutting edge. The other components are available immediately. A trade-off between the investment costs of assembly equipment and the transportation costs of the tool is usually made according to instincts and empirical values instead of a scientific optimization approach. 3. Approaches for assessing complexity in cutting tool management Regarding the assessment of complexity in cutting tool management, product complexity and process complexity need to be evaluated separately. 3.1. Tool portfolio and interface analysis (product complexity) For dealing with complexity in cutting tool management, a deep understanding of the used components is necessary. One possibility of visualizing the complexity is drawing Variant Trees. Frequently, they are mapped for visualizing the increasing variety during the assembly process. Doing this, all components of a product are connected by lines according to their assembly. This method can easily be adapted to cutting tools as described in the following. On the root, all machine tools are located. The edges from the machine tools lead to the tool holders of the tools used on these machines. The next edges lead to the components being attached to the tool holder. This procedure is done until all components are added to the tree. Each path represents one entire tool used on the machine tool considered. Other visualizations such as for various machine tools may be useful as well. For further analyses, information is added like the processing time on the machine tool (based on a significant time period). Additionally, the times for assembling the components can be added to the edges. An exemplary Variant Tree is shown in Figure 4. The numbers next to the components represent the processing time on the machine tool which can exemplarily be extracted from the work plans (before processing) or from the machine control or by using tracking technology such as Radio Frequency Identification (during or after processing). Taking a time period of 24 hours (h), tool holder 1 is in use for 8 h being connected to adapter 1 for 2 h, which is connected to the cutting edge holder for 1 h, which is equipped with cutting edge 1 for 0.5 h. 2h 8h 24h Machine tool 1

Tool holder 1

…

Adapter 1 … Cutting edge holder 2 …

Cutting edge holder 1 …

1h

of these indicators, adjustments of the tool portfolio are done. As an extension, the standardization degree of components can be calculated by dividing the number of production orders using the component by the total number of production orders. These indicators do not consider interfaces. However, the interface standardization degree for all tool components specified in chapter 2.3, namely the tool holder, the adapter, the cutting edge holder and the cutting edge, should be calculated as well. Since each component comprises two interfaces, two figures for all tool components are needed. These indicators are the basis for making adjustments in the tool spectrum. On top of considering the individual components and interfaces, a closer look should be taken on the combinations of two or more components. Among others, this is needed to draw conclusions regarding the optimal degree of assembly based on operating time. For this, the duration of use for the combinations should be calculated. In the example, adapter 1 and tool holder 1 are needed for two hours on machine tool 1. The demand of all other machine tools should be added to this providing the total demand for this combination. Further analyses regarding the usage of the components in other combinations (e.g. tool holder 1 and cutting edge holder 2), the assembly costs, the transportation times and the capital commitment costs are necessary. First approaches for assessing the complexity with a Variant Tree were provided in this sector. However, a deeper analysis of all influencing factors is needed. 3.2. Tool cycle analysis (process complexity) Various approaches for assessing the complexity of processes exist. One of the approaches most suitable for tool management is the Petri-Net, first introduced by Petri [24] in 1962. Petri-Nets not only visualize the structure but also the material flow of the system. An additional advantage is the modelling of concurrencies, meaning that the elements can work simultaneously [25]. In the context of tool management, this is an important characteristic because the work stations in the tool cycle work independently. Places are passive and transitions are active elements. 120s

60s

A

20s

3

TH,A, CEH,CE TH,A

CEH 20s

…

Cutting edge 3

TH,A,CEH

TH

0.5h Cutting edge 1

1503 5

CE

CEH,CE

80s

3

…

Cutting edge 2 …

Figure 4: Variant Tree for cutting tools

Indicators for assessing the relationships should be defined. Leinhäuser [3] exemplarily defines the entire tools’ static standardization degree which is calculated by dividing the number of production orders using the tool by the total number of production orders. The dynamic standardization degree is calculated by referring to a specific time period. On the basis

Figure 5: Assembly process visualized in a Petri-Net

In the example illustrated in Figure 5, the assembly process is modelled with a Petri-Net, showing the upper branch of the example in Figure 4. The transitions represent the assembly process. They are activated if the places before are filled with the required number of tokens. In the places at the left side of the figure, the tokens represent the individual components. In the example in Figure 5 this means, that one tool holder (TH), one adapter (A), one cutting edge holder (CEH) and three

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cutting edges (CE) are available. The numbers on the edges indicate how many tokens are needed until the transition can fire. Due to clarity reasons, in the example only the edges transporting more than one token are labelled. As soon as all components are available respectively the required number of tokens are in the places, the assembly process starts respectively the transition fire. Therefore, in the places after the first transition, the tokens represent assembled components. The token in the last place, labelled “TH,A,CEH,CE” represents the entire tool. In the example, CEH and CE can be assembled first. Alternatively, CE can also be mounted later if TH, A and CEH are already assembled. The average time needed for the assembly process is written next to the transition. Exemplarily, the assembly of CEH and CE takes 20 s, the one of TH and A 60 s and the one of TH, A and CEH 120 s. Adding the assembled module TH,A to CEH,CE takes another 80 s whereas adding CE and TH,A,CEH takes 20 s. For simplification purposes, the upper branch (assembling TH,A,CEH first and then CE) is neglected in the following calculation. In this case, the overall assembly time (AT) ranges from 140 s (parallelization of processes) as seen in Formula 1 to 160 s (sequential processes).  = max20; 60 + 80 = 140

(1)

The comprehensive view of the assembly process of several tools may lead to the conclusion that some components can stay assembled as a module and be used for various tools. This reduces the assembly time. If, for example TH,A is needed for other applications as well, it may save 60 s preparation time. It also assists in defining an optimal tool inventory level because the Net visualizes the number of components (tokens) in the various storage areas (places). The authors assume that Petri-Nets offer further potential for optimizing tool management which has to be investigated. 4. Conclusion and outlook A high product variety leads to an increased tool variety and more frequent tool changes are necessary. Under these conditions, ensuring a high tool availability and keeping inventory levels low is more difficult than in low-variety environments. Modularization is one method for achieving a high tool availability and reducing tool inventories at the same time. However, it increases the complexity of the tool cycle due to various combination possibilities and routing options. For efficiently preventing, reducing and managing complexity, the relationships have to be understood and assessed. In this paper, the components were explained with focus on their interfaces and the assembly process. Next, measures for assessing complexity were described and further research needs identified. A suitable method for assessing the product complexity is the Variant Tree. Petri-Nets are useful for visualizing the process complexity. Some indicators for assessing the product and process complexity were defined. However, further ones for assessing the complexity of the

cutting tool itself and the tool cycle need to be developed since they serve as a basis for deriving recommendations of action to manage the complexity and ensure a high tool availability and low tool inventories. References [1] German Federal Ministry for Economic Affairs and Energy, editor. Industrie 4.0. Berlin; 2015. [2] Geib T. Geschäftsprozessorientiertes Werkzeugmanagement. Diss. Wiesbaden: Gabler-Verlag; 1997. [3] Leinhäuser U. Optimierung von Leistungen und Kosten des Werkzeugwesens in spanenden Fertigungen. Diss. Düsseldorf: VDI Verlag; 1996. [4] Mumm A. Analyse und Gestaltung von Werkzeugversorgungssystemen in der spanenden Fertigung. Diss. Essen: Vulkan-Verlag; 1999. [5] Witte H.-H. Methoden zur Gestaltung der Werkzeugversorgung in spanenden Fertigungen. Diss. Düsseldorf: VDI-Verlag; 1994. [6] Müller U. Konzeption zur systematischen Planung und Steuerung des Werkzeugwesens im Sinne des Ereignisorientierten Tool-Managements. Diss. Aachen: Shaker Verlag; 2004. [7] Klabunde S. Wissensmanagement in der integrierten Produkt- und Prozessgestaltung: Best-Practice-Modelle zum Management von MetaWissen. 1st ed. Wiesbaden: DUV; 2003. [8] Meyer C. Integration des Komplexitätsmanagements in den strategischen Führungsprozess der Logistik. Bern: Haupt; 2007. [9] Miragliotta G, Perona M, Portioli-Staudacher A. Complexity management in the supply chain: theoretical model and empirical investigation in the italian household appliance industrie. In: Seuring S, editor. Cost management in supply chains. Berlin: Springer; 2002. pp. 381-397. [10] Serdarasan S. A review of supply chain complexity drivers. Computers and Ind Eng, 2013; 66. pp. 533-540. [11] Monostori L, Kádár B, Bauernhansl T, Kondoh S, Kumara S, Reinhart G, Sauer O, Schuh G, Sihn W, Ueda K. Cyber-physical systems in manufacturing. CIRP Annals Man Techn, 2016; 65. pp. 621-641. [12] ElMaraghy W, ElMaraghy H, Tomiyama T, Monostori L. Complexity in engineering design and manufacturing. CIRP Annals Man Techn, 2012; 61. pp. 793-814. [13] Kohr D, Budde L, Friedli T. Identifying complexity drivers in discrete manufacturing process industry. Procedia CIRP, 2017; 63. pp. 52-57. [14] Romberg A. Konzept zur systematischen, betriebsspezifischen Analyse und Neustrukturierung des Werkzeugwesens im Sinne des integrierten Toolmanagements. Diss. Karlsruhe: Ernst Grässer; 1993. [15] Weck M, Brecher C. Werkzeugmaschinen und Maschinenarten und Anwendungsbereiche. 6th ed. Berlin Heidelberg: Springer; 2005. [16] Attig P. Komplexitätsreduktion in der Logistik durch modulare Sonderladungsträger. Diss. Aachen: Apprimus Verlag; 2011. [17] Browning T. Applying the design structure matrix to system decomposition and integration problems: a review and new directions. IEEE Transactions on Eng Mgmt, 2001; 48 (3). pp. 292-306. [18] Ulrich K. The role of product architecture in the manufacturing firm. Research Policy, 1995; 24. pp. 419-440. [19] The free dictionary. URL: http://de.thefreedictionary.com/komponenten. accessed on December 21st 2017. [20] DIN4000-95. Tabular layout of properties - Part 95: Interface coding for tools and clamping devices. Berlin: Beuth-Verlag; 2016. [21] Heisel U, Klocke F, Uhlmann E, Spur G. Fräsen. In: Spur G (editor). Handbuch Spanen. 2nd ed. München: Carls Hanser Verlag; 2014. pp. 309395. [22] Heisel U, Klocke F, Uhlmann E, Spur G. Bohren, Senken und Reiben. In: Spur G (editor). Handbuch Spanen. 2nd ed. München: Carls Hanser Verlag; 2014. pp. 397-452. [23] DIN1835-1. Parallel shanks for milling cutters - Part 1: Dimensions. Berlin: Beuth-Verlag; 1999. [24] Petri A. Kommunikation mit Automaten. Diss; 1962. [25] Becker J, Probandt W, Vering O. Grundsätze ordnungsmäßiger Modellierung. Berlin Heidelberg: Springer-Gabler; 2012.