- Email: [email protected]
Dispatching and expediting
Chapter 25
Dispatching and expediting Chapter takeaways After completion of this chapter the reader would be able to 1. Distinguish between loading a dispatching and expediting of the production planning and control (PP&C) activities so as to plan and exercise effective production control. 2. Understand the functions of dispatching and expediting to be able to plan and perform effective PP&C activities. 3. Understand the data to be filled in each PP&C format, like work order, move order, and time ticket to develop customized formats for a particular application. 4. Learn about the visual control charts that can be used in communicating with the ship floor operatives. 5. Learn about Gantt chart and Sched-U graphs to develop customized charts for the type of industry. 6. Understand the details that should be discussed during periodic review meetings to develop ideal progress report sheets.
25.1 Dispatching Dispatching is the transition stage after scheduling and loading, involving the routine of setting production activities in motion through the release of orders and instructions in accordance with previously planned schedules and sequences specified in the route sheets. It translates the paperwork into actual production and coordinates planning into actual production, ensuring that all production material and other aids are ready when needed and then getting them issued to manufacturing departments at the point at which they are needed.
25.2 Definitions on dispatching Dispatching refers to the control of processes of operation planning, giving operation order and controlling operations in the manufacturing site. http://www.asprova.jp/
Production Planning and Control. DOI: https://doi.org/10.1016/B978-0-12-818364-9.00025-1 Copyright © 2019 BSP Books Pvt. Ltd. Published by Elsevier Inc. All rights reserved.
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Dispatching may be defined as setting production activities in motion through the release of orders (work order, shop order) and instructions in accordance with the previously planned time schedules and routings. http://www.citeman.com/ Dispatching is the transition from planning phase to action phase. In this phase, the worker is ordered to start manufacturing the product. Dispatching involves the actual granting of permission to proceed according to plans already laid down. In dispatching, orders are issued in terms of their priority. http://kkhsou.in/main/EVidya2/management/production_planning.html Dispatching is a function of Production controlling. It ensures the timely movement of semi-finished items from one machine to another machine. Ultimately the target set at the stage of production planning are achieved with the help of this dispatching function, because it deals with the movement of semi-finished items from one machine to another within a specified time frame. http://www.answers.com/ Dispatching is the part of production control that translates the paper work into actual production. It is the group that coordinates and translates planning into actual production. Dispatching function proceeds in accordance with the details worked out under routing and scheduling functions. As such, dispatching sees to it that the material is moved to the correct work place, that tools are ready at the correct place for the particular operations that the work is moving according to routing instructions. Dispatching carries out the physical work as suggested by scheduling. Thus, dispatching implies the issuance or work orders. These work orders represent authority to produce. These orders contain the following information: faculty.mu.edu.sa
25.3 Principles of dispatching 1. Dispatching is concerned with giving written instructions to actually start the production. 2. It involves issuing production orders for starting the operations. 3. Plans laid out by routing and scheduling actually are the basis for dispatching and the movement of materials to different workstations. 4. Dispatching authorizes the worker or foreman to receive materials tools, jigs, and fixtures and to proceed with a given job. 5. It ensures movement of work from one operation to another in accordance with the route sheet. 6. It involves releasing forms for every order that carry written instructions to the people concerned.
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7. It involves the actual granting of permission to proceed according to plans already laid down. 8. It also involves supervision of work to some extent regarding the following of standard operating procedure. 9. It informs the process section that production is commencing.
25.4 The functions of dispatching The dispatch section of the production planning and control (PPC) is responsible for the following tasks: 1. Dispatching is an important step, as it translates production plans into actual production. 2. Primary function of dispatching is to prepare manufacturing orders that consist of shop orders, move orders, tool orders, etc. These are to be issued at the right time to the concerned persons. 3. Release of necessary order and production forms is needed so that the operations can be started. 4. Issuing of drawings, specifications, route cards, material requisitions, and tool requisitions to the user department. 5. Withdraw required quantity of material from the stores and deliver to the work center where the first operation is to be complete through stores’ issue order. 6. Checking the availability of material and then taking appropriate action to have it transferred from the main stores to the point at which it is needed. 7. Ensure that all production aid is ready when needed and then having them issued to manufacturing departments. 8. Internal materials handling and movement of materials to the inspection area after completing the operation, moving the materials to the next operation center after inspection, and movement of completed parts to holding stores. 9. Issuing of tools required for production and returning them to the stores after completion of the work orders. 10. Issue of move order for interdepartmental transport. 11. Stage inspection. 12. Coordination with scheduling. 13. Forwarding materials to dispatch or to finished parts stores. 14. After completing the scheduled operation, ensure that all the drawings, layout, and tools are withdrawn and returned to their correct location.
25.5 Documents raised for dispatching These are explained in Chapter 27, Systems and procedures, and illustrated in the relevant formats.
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Material warrants cum progress card Work order/Job card Time ticket Move order Inspection order
25.6 Expediting This is also called progressing or production chasing. Progressing is that part of the production control function that is responsible for making routine comparisons between production performance and production plans and for reporting exceptional variance so that they can be corrected, as explained in the previous paragraph. By giving early warning when actual production deviates from planned production, it becomes possible for corrective action to be taken in order to regain the desired course. Progressing in the production control completes the loop of production control. In summary, the purposes of the active functions of dispatching and expediting are the following: 1. The basic function of expediting is to check to ensure that all materials, tools, component parts, and accessories are available at all work centers in specified quantities for starting and carrying out manufacturing operations. 2. To release the production orders at the appropriate time and facilitate effective flow of information. 3. To check on the status of work-in-progress and completed work at various workstations. This includes collecting information relating to the starting and completion time and date of work completed; status of work-in-progress relative to scheduled completion dates, position of movements of materials, component parts, and subassemblies within the plant; and inspection results. 4. To record the flow of material and tools and adjust whenever necessary. 5. To record progress of production operations and expedite where necessary. 6. To record amount of work in process and verify its effect on the schedule. 7. To record quantities produced and compare with required quantities. 8. To record amount of faulty work and scrap and issue orders for production of replacements. 9. To record machine idle time and check the reasons for it. 10. To record stoppages and holdups and classify them according to a. Waiting for drawings or instruction b. Lack of materials c. Failure of tools d. Work held up by previous operation
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e. Machine breakdown f. Operator missing or not available g. Waiting for inspection to approve h. Work or machine setting 11. Last is to report to the management on all significant deviations so that corrective action may be taken. It also includes reporting to the production planning department so that future plans may be adjusted. Some of the factors that may cause production holdups or delay, for which the expediters have to be constantly on the lookout, are the following: 1. 2. 3. 4. 5. 6. 7.
Materials may be delivered late or may not be delivered at all. Associated departments may have fallen behind in their own production. There may be excessive absenteeism on the part of the worker. The customer may insist on changing the specification or delivery date. Excessive breakdown of machinery, jigs, fixtures, etc. There may be errors in drawings and process plans. There may be too many rejections due to poor material quality.
25.7 Other uses of these records While Chapter 27, Systems and procedures, deals more on these formats, we may cite their uses in the functioning of the production planning and control (PP&C) department in general: G
G
G
G
G
G
G
G
Calculating wages, if the wage scheme in the plant is dependent on output. Examining the cost of the job and the product and comparing with the planned budget and the initial cost estimates. Comparing operating times with the estimated times and verifying whether the discrepancies are consistent with past experience so that future estimates can be made more accurate. Locating weak points in the production line, so that work study can be undertaken to explore ways of alleviating the difficulties. Studying how much idle time was caused because of scheduling interference (i.e., overlap in operation times) due to unaccountable delays or too tight a production schedule. Studying how much delay was caused by machine breakdown and the maintenance of the situation. This analysis could lead to an optimal number of repairmen required, the amount of effort that should be devoted to preventive maintenance leading to an optimal maintenance schedule. Analyzing the delays caused by tool breakdowns, reworking, and resetting and to ensure that the specified speeds are compatible with reasonable amount of tool wear. Analyzing to what extent both queues and delays are caused by inadequate materials handling systems.
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25.8 Follow-up After setting production in motion, we have to ensure that it is proceeding according to the plan. This determination of the progress of work, removing bottlenecks in the flow of work, and ensuring that the productive operations are taking place in accordance with the plans is called follow-up, which is an extension of expediting and includes inspecting the work progress, and evaluating the effectiveness. 1. Follow-up can be defined as checking the actual production progress in accordance with the production program laid out by routing and scheduling. 2. This is done to regulate production through various processes. 3. Daily progress is reported in a prescribed pro forma highlighting the reasons for the nonperformance or bottlenecks. 4. Adherence to schedule and falling short of delivery dates are monitored. 5. Follow-up function is to make sure that a. The materials and other accessories should reach shops in the required time, as per schedule. b. A given order undergoes all operations as given by routing. c. All parts for assembly are ready in required quantities before assembly.
25.9 Progress reporting We have seen in the earlier chapters that the three fundamental aspects of effective production are planning, control, and reporting. It should be ensured that the production targets planned in terms of quantities and types of products to be produced within a given time frame are achieved as per the production scheduling. A day-to-day feedback on the progress and any deviation from the schedule is to be reported by the planning department or the production control supervisor to the management. Business Dictionary defines progress reporting as an assessment that takes place during a production process that conveys details such as what subgoals have been accomplished, what resources have been expended, what problems have been encountered, and whether the project or process is expected to be completed on time and within budget. Progress reports are used by management to determine whether changes are necessary to an ongoing effort. Based on feedback weekly or daily as required, production meetings will be held among the departmental heads, planning engineer, and the works manager for review. The efficiency of the production planning systems lies in quick recording, quick actions, and getting quick decisions.
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25.10 Visual control charts Visual control charts are business management gadgets used to communicate information on what has been scheduled and what has actually been achieved by using visual signals, mostly painted, printed, or hand-drawn charts instead of texts or other written reports. The production controller is significantly supported by these charts and other graphical tools to visualize much information at a glance.
25.10.1 The characteristics of visual charts G G
G
G G
G
They are used for monitoring or controlling any aspect of production. They are posted at the plant site very near the place where the actual work is done. They are frequently updated with the latest results, not just historical post mortems. They respond to and highlight problems graphically. They clearly articulate the reasons for “misses” (differences between expected vs. actual results). They can be understood by a newcomer standing 10 ft away.
25.10.2 Some of the charts used in production control 1. 2. 3. 4.
Gantt charts Sched-U graphs Visual control charts Cumulative and weekly charts.
25.11 Gantt chart Gantt charts are bar charts that illustrate the start and finish dates of the terminal elements and summary elements of a project showing activities (tasks or events) displayed against time. In 1896, Karol Adamiecki, a Polish engineer, was the first to devise a time-based chart to represent the activities in chart forms to enhance the visibility of production schedules. Henry Gantt, an American engineer and management consultant, modified this chart in his own version as Gantt chart in 1910, which became widely known and popular in Western countries. In a Gantt chart, the activities are listed one below the other on the left, and each activity is represented by a bar on a time scale with the position and length of the bar reflecting the start date, duration, and end date of the activity. Gantt charts allow us to visualize at a glance, G G
What the various activities are. When each activity begins and ends.
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How long each activity is scheduled to last. Where activities overlap with other activities, and by how much. The start and end dates of the whole project.
25.11.1 Gantt chart for project control versus production control Most Gantt charts are drawn for the project control indicating the scheduled activities and the actual dates for the completion of those activities. Gantt charts can also be drawn to indicate the scheduled output of component production for the PP&C function. Fig. 25.1 illustrates the Gantt chart suitable for Project control, and Fig. 25.2 illustrates the Gantt chart maintained by this author for the PP&C function in a medium-scale petrol engine manufacturing unit during the 1970s. Noted that the actual operations started earlier than scheduled but took longer time to complete.
FIGURE 25.1 A Gantt chart for project controlling.
FIGURE 25.2 A Gantt chart for production controlling.
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25.11.2 Gantt chart symbols 1. Work tasks can be represented either by numbers or special symbols. 2. The numbers used indicate the number of units to be produced within the specific time. 3. Some of the symbols used in Gantt chart are shown in (Fig. 25.3). The following abbreviations may also be used below the actual production line, if the actual is significantly different from the scheduled. G G G G G
AOperator absent IInstruction lacking or not clear RMMaterial not available MMachine under repair TTool change or repair
25.11.3 Characteristics of Gantt charts 1. A Gantt chart is a principal tool used in scheduling and loading. 2. It consists of a grid where the vertical lines divide the horizontal lines in units of time, with the X-axis representing time. 3. Horizontal lines represent either work tasks or work centers (machines). 4. When work centers are represented in horizontal lines, it is a case of loading. 5. When work tasks are represented in horizontal lines, it is a case of scheduling. 6. A chart that gives both work tasks and work centers is called a load chart.
25.12 Sched-U graphs During the 1970s, the Gantt charts were prepared laboriously by hand. Whenever the base time period was over, the charts were drawn again with
FIGURE 25.3 Gantt chart symbols.
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the same or different products and activities This limited their usefulness, continual change being a feature of most activities. Subsequently, Sched-U Graphs, similar to the Gantt charts, were developed. These are a variation of the Gantt chart, with their purpose being more visual in nature. They present a current picture of the situation but leave no record of past events. Visual charts often make use of colored bars, strings, moveable rulers, meters with numbers, etc. Instead of pencil-drawn bars, they have colored sticker strips that are available in the form of rolls. These are cut to desired lengths and stuck on a board with preprinted details. These Sched-U graphs are further modified by replacing the colored strips by spring-loaded colored threads, which can be pulled out horizontally and fixed at the desired time position.
25.13 Other visual control charts The advent of computers and project management software have made creation, preparation updating, and printing of these charts much easier. New computer software like MindView Business, Active Collab, and FastTrack Schedule are available to manage task information from start to finish in a matter of seconds, thus permitting very frequent review of the actual shop situation. Wikipedia lists and compares several such software, https://en.wikipedia.org/wiki/Comparison_of_project_management_software
25.14 Weekly cumulative charts Apart from the visual charts that are normally kept on the shop floor to be visible to all concerned, the PP&C department periodically prepares a weekly report indicating the actual vs scheduled production of each component or the outputs of critical machines. This would be presented during the weekly review meeting convened by the factory manager with all the departmental heads.
25.15 Conclusion No amount of perfect planning can be effective unless proper control is exercised to implement and execute these plans. We have thus seen in this chapter the typical PP&C tools to achieve this. The function of expediting has become so significant in industry that even though the operatives refer to them as chasers or whip-masters, the expediters are known to achieve very positive results in ensuring the actual production is as per the schedules, by maintaining good relations with the operatives.
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Further reading 1. Eilon, S., 1962. Elements of Production Planning & Control, Macmillan, New York. 2. Kiran, D.R., 2015. Total Quality Management, An Integrated Approach. BS Publications, Hyderabad. 3. www.thefreedictionary.com/dispatching. 4. https://cdict.net/q/dispatching. 5. www.asprova.jp . . . . . Manufacturing Planning and Process Controls 6. www.citeman.com/182-production-control-functions. 7. faculty.mu.edu.sa/download.php?fid 5 32563. 8. arxiv.org/pdf/1407.2709 by K Wu. 9. https://en.wikipedia.org/wiki/Expediting. 10. www.valuestreamguru.com. 11. searchsoftwarequality.techtarget.com/definition/Gantt-chart. 12. www.gantt.com. 13. www.mindtools.com. 14. searchsoftwarequality.techtarget.com. Criteria questions (The figures in the bracket provide a clue to the answer.) Dispatching 1. What is meant by dispatching? (25.1) 2. Explain briefly the dispatching activities. (25.4) 3. Explain the necessity of close control in dispatching activities. (25.3) 4. How does dispatching in a continuous flow system differ from dispatching in an intermittent order system? (25.3) 5. Enumerate the duties of a dispatcher. (25.4) 6. List some of the documents raised for dispatching. Discuss the significance of a material warrant. (25.6) 7. What is the difference between a work order and move order? Illustrate. (25.6) 8. List the merits and demerits of centralized and decentralized systems of dispatching. (25.4) Expediting 1. Explain expediting. How does it differ from dispatching? (25.7) 2. In what ways do you classify the production holdups? (25.8) 3. Briefly explain chase planning. (25.8) 4. Briefly explain the different types of follow-up. (25.8) Progress reporting 1. What purpose does progress reporting serve? (25.9) 2. Why are progress reports required in manufacturing industries? (25.9) 3. Briefly explain the different types of progress reports. (25.10) 4. Explain the use of Gantt charts in a batch industry. (25.11)
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5. Explain with a neat sketch how a Gantt chart is used to show schedules. Explain the symbols used in drawing a Gantt chart. (25.11) 6. Distinguish between a Gantt progress chart and a Gantt load chart. (25.11) 7. Explain the schedule boards and commercial devices. (25.12) 8. Distinguish between a Gantt chart and Sched-U graph. (25.12) 9. Give the specimen of a schedule chart. (25.12) 10. Explain the schedule chart used for large-sized articles, for example, construction of a railway coach. (25.12) 11. Explain a cumulative production schedule graph. (25.14)
Dispatching and expediting Chapter takeaways After completion of this chapter the reader would be able to 1. Distinguish between loading a dispatching and expediting of the production planning and control (PP&C) activities so as to plan and exercise effective production control. 2. Understand the functions of dispatching and expediting to be able to plan and perform effective PP&C activities. 3. Understand the data to be filled in each PP&C format, like work order, move order, and time ticket to develop customized formats for a particular application. 4. Learn about the visual control charts that can be used in communicating with the ship floor operatives. 5. Learn about Gantt chart and Sched-U graphs to develop customized charts for the type of industry. 6. Understand the details that should be discussed during periodic review meetings to develop ideal progress report sheets.
25.1 Dispatching Dispatching is the transition stage after scheduling and loading, involving the routine of setting production activities in motion through the release of orders and instructions in accordance with previously planned schedules and sequences specified in the route sheets. It translates the paperwork into actual production and coordinates planning into actual production, ensuring that all production material and other aids are ready when needed and then getting them issued to manufacturing departments at the point at which they are needed.
25.2 Definitions on dispatching Dispatching refers to the control of processes of operation planning, giving operation order and controlling operations in the manufacturing site. http://www.asprova.jp/
Production Planning and Control. DOI: https://doi.org/10.1016/B978-0-12-818364-9.00025-1 Copyright © 2019 BSP Books Pvt. Ltd. Published by Elsevier Inc. All rights reserved.
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Dispatching may be defined as setting production activities in motion through the release of orders (work order, shop order) and instructions in accordance with the previously planned time schedules and routings. http://www.citeman.com/ Dispatching is the transition from planning phase to action phase. In this phase, the worker is ordered to start manufacturing the product. Dispatching involves the actual granting of permission to proceed according to plans already laid down. In dispatching, orders are issued in terms of their priority. http://kkhsou.in/main/EVidya2/management/production_planning.html Dispatching is a function of Production controlling. It ensures the timely movement of semi-finished items from one machine to another machine. Ultimately the target set at the stage of production planning are achieved with the help of this dispatching function, because it deals with the movement of semi-finished items from one machine to another within a specified time frame. http://www.answers.com/ Dispatching is the part of production control that translates the paper work into actual production. It is the group that coordinates and translates planning into actual production. Dispatching function proceeds in accordance with the details worked out under routing and scheduling functions. As such, dispatching sees to it that the material is moved to the correct work place, that tools are ready at the correct place for the particular operations that the work is moving according to routing instructions. Dispatching carries out the physical work as suggested by scheduling. Thus, dispatching implies the issuance or work orders. These work orders represent authority to produce. These orders contain the following information: faculty.mu.edu.sa
25.3 Principles of dispatching 1. Dispatching is concerned with giving written instructions to actually start the production. 2. It involves issuing production orders for starting the operations. 3. Plans laid out by routing and scheduling actually are the basis for dispatching and the movement of materials to different workstations. 4. Dispatching authorizes the worker or foreman to receive materials tools, jigs, and fixtures and to proceed with a given job. 5. It ensures movement of work from one operation to another in accordance with the route sheet. 6. It involves releasing forms for every order that carry written instructions to the people concerned.
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7. It involves the actual granting of permission to proceed according to plans already laid down. 8. It also involves supervision of work to some extent regarding the following of standard operating procedure. 9. It informs the process section that production is commencing.
25.4 The functions of dispatching The dispatch section of the production planning and control (PPC) is responsible for the following tasks: 1. Dispatching is an important step, as it translates production plans into actual production. 2. Primary function of dispatching is to prepare manufacturing orders that consist of shop orders, move orders, tool orders, etc. These are to be issued at the right time to the concerned persons. 3. Release of necessary order and production forms is needed so that the operations can be started. 4. Issuing of drawings, specifications, route cards, material requisitions, and tool requisitions to the user department. 5. Withdraw required quantity of material from the stores and deliver to the work center where the first operation is to be complete through stores’ issue order. 6. Checking the availability of material and then taking appropriate action to have it transferred from the main stores to the point at which it is needed. 7. Ensure that all production aid is ready when needed and then having them issued to manufacturing departments. 8. Internal materials handling and movement of materials to the inspection area after completing the operation, moving the materials to the next operation center after inspection, and movement of completed parts to holding stores. 9. Issuing of tools required for production and returning them to the stores after completion of the work orders. 10. Issue of move order for interdepartmental transport. 11. Stage inspection. 12. Coordination with scheduling. 13. Forwarding materials to dispatch or to finished parts stores. 14. After completing the scheduled operation, ensure that all the drawings, layout, and tools are withdrawn and returned to their correct location.
25.5 Documents raised for dispatching These are explained in Chapter 27, Systems and procedures, and illustrated in the relevant formats.
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1. 2. 3. 4. 5.
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Material warrants cum progress card Work order/Job card Time ticket Move order Inspection order
25.6 Expediting This is also called progressing or production chasing. Progressing is that part of the production control function that is responsible for making routine comparisons between production performance and production plans and for reporting exceptional variance so that they can be corrected, as explained in the previous paragraph. By giving early warning when actual production deviates from planned production, it becomes possible for corrective action to be taken in order to regain the desired course. Progressing in the production control completes the loop of production control. In summary, the purposes of the active functions of dispatching and expediting are the following: 1. The basic function of expediting is to check to ensure that all materials, tools, component parts, and accessories are available at all work centers in specified quantities for starting and carrying out manufacturing operations. 2. To release the production orders at the appropriate time and facilitate effective flow of information. 3. To check on the status of work-in-progress and completed work at various workstations. This includes collecting information relating to the starting and completion time and date of work completed; status of work-in-progress relative to scheduled completion dates, position of movements of materials, component parts, and subassemblies within the plant; and inspection results. 4. To record the flow of material and tools and adjust whenever necessary. 5. To record progress of production operations and expedite where necessary. 6. To record amount of work in process and verify its effect on the schedule. 7. To record quantities produced and compare with required quantities. 8. To record amount of faulty work and scrap and issue orders for production of replacements. 9. To record machine idle time and check the reasons for it. 10. To record stoppages and holdups and classify them according to a. Waiting for drawings or instruction b. Lack of materials c. Failure of tools d. Work held up by previous operation
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e. Machine breakdown f. Operator missing or not available g. Waiting for inspection to approve h. Work or machine setting 11. Last is to report to the management on all significant deviations so that corrective action may be taken. It also includes reporting to the production planning department so that future plans may be adjusted. Some of the factors that may cause production holdups or delay, for which the expediters have to be constantly on the lookout, are the following: 1. 2. 3. 4. 5. 6. 7.
Materials may be delivered late or may not be delivered at all. Associated departments may have fallen behind in their own production. There may be excessive absenteeism on the part of the worker. The customer may insist on changing the specification or delivery date. Excessive breakdown of machinery, jigs, fixtures, etc. There may be errors in drawings and process plans. There may be too many rejections due to poor material quality.
25.7 Other uses of these records While Chapter 27, Systems and procedures, deals more on these formats, we may cite their uses in the functioning of the production planning and control (PP&C) department in general: G
G
G
G
G
G
G
G
Calculating wages, if the wage scheme in the plant is dependent on output. Examining the cost of the job and the product and comparing with the planned budget and the initial cost estimates. Comparing operating times with the estimated times and verifying whether the discrepancies are consistent with past experience so that future estimates can be made more accurate. Locating weak points in the production line, so that work study can be undertaken to explore ways of alleviating the difficulties. Studying how much idle time was caused because of scheduling interference (i.e., overlap in operation times) due to unaccountable delays or too tight a production schedule. Studying how much delay was caused by machine breakdown and the maintenance of the situation. This analysis could lead to an optimal number of repairmen required, the amount of effort that should be devoted to preventive maintenance leading to an optimal maintenance schedule. Analyzing the delays caused by tool breakdowns, reworking, and resetting and to ensure that the specified speeds are compatible with reasonable amount of tool wear. Analyzing to what extent both queues and delays are caused by inadequate materials handling systems.
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25.8 Follow-up After setting production in motion, we have to ensure that it is proceeding according to the plan. This determination of the progress of work, removing bottlenecks in the flow of work, and ensuring that the productive operations are taking place in accordance with the plans is called follow-up, which is an extension of expediting and includes inspecting the work progress, and evaluating the effectiveness. 1. Follow-up can be defined as checking the actual production progress in accordance with the production program laid out by routing and scheduling. 2. This is done to regulate production through various processes. 3. Daily progress is reported in a prescribed pro forma highlighting the reasons for the nonperformance or bottlenecks. 4. Adherence to schedule and falling short of delivery dates are monitored. 5. Follow-up function is to make sure that a. The materials and other accessories should reach shops in the required time, as per schedule. b. A given order undergoes all operations as given by routing. c. All parts for assembly are ready in required quantities before assembly.
25.9 Progress reporting We have seen in the earlier chapters that the three fundamental aspects of effective production are planning, control, and reporting. It should be ensured that the production targets planned in terms of quantities and types of products to be produced within a given time frame are achieved as per the production scheduling. A day-to-day feedback on the progress and any deviation from the schedule is to be reported by the planning department or the production control supervisor to the management. Business Dictionary defines progress reporting as an assessment that takes place during a production process that conveys details such as what subgoals have been accomplished, what resources have been expended, what problems have been encountered, and whether the project or process is expected to be completed on time and within budget. Progress reports are used by management to determine whether changes are necessary to an ongoing effort. Based on feedback weekly or daily as required, production meetings will be held among the departmental heads, planning engineer, and the works manager for review. The efficiency of the production planning systems lies in quick recording, quick actions, and getting quick decisions.
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25.10 Visual control charts Visual control charts are business management gadgets used to communicate information on what has been scheduled and what has actually been achieved by using visual signals, mostly painted, printed, or hand-drawn charts instead of texts or other written reports. The production controller is significantly supported by these charts and other graphical tools to visualize much information at a glance.
25.10.1 The characteristics of visual charts G G
G
G G
G
They are used for monitoring or controlling any aspect of production. They are posted at the plant site very near the place where the actual work is done. They are frequently updated with the latest results, not just historical post mortems. They respond to and highlight problems graphically. They clearly articulate the reasons for “misses” (differences between expected vs. actual results). They can be understood by a newcomer standing 10 ft away.
25.10.2 Some of the charts used in production control 1. 2. 3. 4.
Gantt charts Sched-U graphs Visual control charts Cumulative and weekly charts.
25.11 Gantt chart Gantt charts are bar charts that illustrate the start and finish dates of the terminal elements and summary elements of a project showing activities (tasks or events) displayed against time. In 1896, Karol Adamiecki, a Polish engineer, was the first to devise a time-based chart to represent the activities in chart forms to enhance the visibility of production schedules. Henry Gantt, an American engineer and management consultant, modified this chart in his own version as Gantt chart in 1910, which became widely known and popular in Western countries. In a Gantt chart, the activities are listed one below the other on the left, and each activity is represented by a bar on a time scale with the position and length of the bar reflecting the start date, duration, and end date of the activity. Gantt charts allow us to visualize at a glance, G G
What the various activities are. When each activity begins and ends.
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How long each activity is scheduled to last. Where activities overlap with other activities, and by how much. The start and end dates of the whole project.
25.11.1 Gantt chart for project control versus production control Most Gantt charts are drawn for the project control indicating the scheduled activities and the actual dates for the completion of those activities. Gantt charts can also be drawn to indicate the scheduled output of component production for the PP&C function. Fig. 25.1 illustrates the Gantt chart suitable for Project control, and Fig. 25.2 illustrates the Gantt chart maintained by this author for the PP&C function in a medium-scale petrol engine manufacturing unit during the 1970s. Noted that the actual operations started earlier than scheduled but took longer time to complete.
FIGURE 25.1 A Gantt chart for project controlling.
FIGURE 25.2 A Gantt chart for production controlling.
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25.11.2 Gantt chart symbols 1. Work tasks can be represented either by numbers or special symbols. 2. The numbers used indicate the number of units to be produced within the specific time. 3. Some of the symbols used in Gantt chart are shown in (Fig. 25.3). The following abbreviations may also be used below the actual production line, if the actual is significantly different from the scheduled. G G G G G
AOperator absent IInstruction lacking or not clear RMMaterial not available MMachine under repair TTool change or repair
25.11.3 Characteristics of Gantt charts 1. A Gantt chart is a principal tool used in scheduling and loading. 2. It consists of a grid where the vertical lines divide the horizontal lines in units of time, with the X-axis representing time. 3. Horizontal lines represent either work tasks or work centers (machines). 4. When work centers are represented in horizontal lines, it is a case of loading. 5. When work tasks are represented in horizontal lines, it is a case of scheduling. 6. A chart that gives both work tasks and work centers is called a load chart.
25.12 Sched-U graphs During the 1970s, the Gantt charts were prepared laboriously by hand. Whenever the base time period was over, the charts were drawn again with
FIGURE 25.3 Gantt chart symbols.
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the same or different products and activities This limited their usefulness, continual change being a feature of most activities. Subsequently, Sched-U Graphs, similar to the Gantt charts, were developed. These are a variation of the Gantt chart, with their purpose being more visual in nature. They present a current picture of the situation but leave no record of past events. Visual charts often make use of colored bars, strings, moveable rulers, meters with numbers, etc. Instead of pencil-drawn bars, they have colored sticker strips that are available in the form of rolls. These are cut to desired lengths and stuck on a board with preprinted details. These Sched-U graphs are further modified by replacing the colored strips by spring-loaded colored threads, which can be pulled out horizontally and fixed at the desired time position.
25.13 Other visual control charts The advent of computers and project management software have made creation, preparation updating, and printing of these charts much easier. New computer software like MindView Business, Active Collab, and FastTrack Schedule are available to manage task information from start to finish in a matter of seconds, thus permitting very frequent review of the actual shop situation. Wikipedia lists and compares several such software, https://en.wikipedia.org/wiki/Comparison_of_project_management_software
25.14 Weekly cumulative charts Apart from the visual charts that are normally kept on the shop floor to be visible to all concerned, the PP&C department periodically prepares a weekly report indicating the actual vs scheduled production of each component or the outputs of critical machines. This would be presented during the weekly review meeting convened by the factory manager with all the departmental heads.
25.15 Conclusion No amount of perfect planning can be effective unless proper control is exercised to implement and execute these plans. We have thus seen in this chapter the typical PP&C tools to achieve this. The function of expediting has become so significant in industry that even though the operatives refer to them as chasers or whip-masters, the expediters are known to achieve very positive results in ensuring the actual production is as per the schedules, by maintaining good relations with the operatives.
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Further reading 1. Eilon, S., 1962. Elements of Production Planning & Control, Macmillan, New York. 2. Kiran, D.R., 2015. Total Quality Management, An Integrated Approach. BS Publications, Hyderabad. 3. www.thefreedictionary.com/dispatching. 4. https://cdict.net/q/dispatching. 5. www.asprova.jp . . . . . Manufacturing Planning and Process Controls 6. www.citeman.com/182-production-control-functions. 7. faculty.mu.edu.sa/download.php?fid 5 32563. 8. arxiv.org/pdf/1407.2709 by K Wu. 9. https://en.wikipedia.org/wiki/Expediting. 10. www.valuestreamguru.com. 11. searchsoftwarequality.techtarget.com/definition/Gantt-chart. 12. www.gantt.com. 13. www.mindtools.com. 14. searchsoftwarequality.techtarget.com. Criteria questions (The figures in the bracket provide a clue to the answer.) Dispatching 1. What is meant by dispatching? (25.1) 2. Explain briefly the dispatching activities. (25.4) 3. Explain the necessity of close control in dispatching activities. (25.3) 4. How does dispatching in a continuous flow system differ from dispatching in an intermittent order system? (25.3) 5. Enumerate the duties of a dispatcher. (25.4) 6. List some of the documents raised for dispatching. Discuss the significance of a material warrant. (25.6) 7. What is the difference between a work order and move order? Illustrate. (25.6) 8. List the merits and demerits of centralized and decentralized systems of dispatching. (25.4) Expediting 1. Explain expediting. How does it differ from dispatching? (25.7) 2. In what ways do you classify the production holdups? (25.8) 3. Briefly explain chase planning. (25.8) 4. Briefly explain the different types of follow-up. (25.8) Progress reporting 1. What purpose does progress reporting serve? (25.9) 2. Why are progress reports required in manufacturing industries? (25.9) 3. Briefly explain the different types of progress reports. (25.10) 4. Explain the use of Gantt charts in a batch industry. (25.11)
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5. Explain with a neat sketch how a Gantt chart is used to show schedules. Explain the symbols used in drawing a Gantt chart. (25.11) 6. Distinguish between a Gantt progress chart and a Gantt load chart. (25.11) 7. Explain the schedule boards and commercial devices. (25.12) 8. Distinguish between a Gantt chart and Sched-U graph. (25.12) 9. Give the specimen of a schedule chart. (25.12) 10. Explain the schedule chart used for large-sized articles, for example, construction of a railway coach. (25.12) 11. Explain a cumulative production schedule graph. (25.14)