Flashcards
Production lecture 4
Cards in this deck (33)
- 1three types of resourcesLand; natural resources (land, raw material)
Labour: human resources
Capital: human-made goods of production (machines, buildings, infrastructure) - 2What is capacity?Capacity in the static, physical sense means the scale of an operation. But this may not reflect the operation's processing capacity. So we must incorporate a time dimension appropriate to the use of assets
- 3Managerial problems regarding capacity planning-Match the capacity with the plans: either to provide sufficient capacity to execute plans or to adjust plans to match capacity constraints
- consciously consider the marketplace implications of faster throughput times for making products, at the expense of reduced capacity utilization - 4What is resource planning?Directly linked to the sales and operations planning module
- 5Master production schedulethe primary information source for rough cut capacity planning. techniques rough-cut capacity planning, which provide information for modifying the resource levels, or material plan to ensure execution of the master production schedule
- 6Capacity requirements planning techniqueMRP to prepare details material plans, a much more detailed capacity plan. Time phased material plans produced by the MRP system form the basis for calculating time phased capacity requirements
- 7Finite loadingA capacity planning procedure. Difference with other capacity planning approaches is that the former set does not consider any adjustment to plans because of planned capacity utilization.
- 8Difference planning and controlplanning is a formalization of what is intended to happen at some time in the future. A plan does not guarantee that an event will actually happen. control is the process of coping with any changes that affect the plan. It may also mean that an 'intervention' will need to be made in the operation to bring it back on track.
- 9Planning and control activitiesSequencing: In what order to do things?
Scheduling: when to do things?
loading: how much to do?
monitoring and control: are activities going to plan? - 10Role of capacity planning and control- To estimate capacity requirements early enough to be able to meet those requirements
To avoid insufficient capacity (leads to bad delivery performance, increased WIP and frustrated personnel) and excess capacity (leads to extra capital cost, overproduction and increased inventories, too much personnel) - 11three methods for rough-cut capacity1. capacity planning using overall factors (CPOF)
2. capacity bills
3. Resource profiles - 12capacity planning using overall factorssimple rough-cut capacity planning approach. used in simple and stable planning environments. successfully; when products are homogeneous from manufacturing point of view. should only be used in environments with flat bill of materials and short lead times compared to the length of the planning period. should be used on long-term planning horizons and with long planning periods. Weeks and months are the most common period lengths.
- 13Advantage capacity planning using overall factorsease of calculation and minimal data requirements, simplicity can be exploited.
- 14Capacity bills- more accurate than CPOF
- it is most common to include several (more than 10) departments/centers in the bills and profiles, i.e. the methods are not primarily used for very broad and long-term planning.
- requires more data than the CPOF - 15Advantage capacity billsit explicitly recognized product mix change. this can be important in JIT operations
- 16Assumption CPOF and capacity billsIf a product has to be finished at the end of a certain period, then the whole product is produced in this period. this assumption is not always realistic.
- 17resource profileadds a further dimension, specific timing of capacity requirements. includes production lead time information. provides time-phased projections of capacity requirements for individual work centers. requires tracking of relatively short time periods (les than 1 week). time periods longer than one week will mask important changes in capacity requirements.
- 18Advantages and disadvantages resource profileAdvantages compared to the previous methods in planning environments with long lead-times. disadvantages; can not consider stock-on-hand for components used in the product.
- 19Difference rough-cut capacity planning and capacity requirement planningRough-cut capacity planning; starts with MPS-data and is long range.
Capacity requirement planning; starts with data MRP and is medium range - 20Capacity requirements planning (CRP)used in more complex environments and for more detailed decisions. used in conjunction with time-phased MRP records and shop-floor system record to calculate capacity required to produce both open shop orders and planned orders. weeks and months are the most common period lengths.
- 21Three strategies for capacity requirements planningforward scheduling, backward scheduling and a mix between forward and backward scheduling. forward scheduling loads an order in a work center as soon as planned capacity is available. backward scheduling takes the job backward from its due date. only large companies use front scheduling.
- 22Advantages and disadvantages CRPadvantages; much more accurate information (especially important for shorter term)
disadvantages; more data required, more calculations, more complexity - 23system constraints- physical constraints (resource constraints); equipment, personnel, materials
- other constraints (policy constraints); management, environment, behavior, lack of information - 24How to make optimal use of the bottleneck capacity-overtime (breaks, at night, weekend)
- alternative routes ( use of other machine)
- larger batch size (less setup time) - 25What is a bottleneckany resource whose capacity is equal to or less than the required demand is referred to as a bottleneck.
- 26Objective/goal of TOCObjective TOC; maximize throughput. goal: always to break a constraint or bottleneck condition, and thereafter identify the next constraints (continuous improvement)
- 27Fundamental principle TOCfundamental principle TOC is that only those work centers that are bottlenecks are of critical concern in scheduling. constraints are explicitly identified and they are buffered with inventory.
- 28TOC scheduling; drum-buffer-ropebottleneck work centers are the drums, and are, therefore used to control the workflow in a plant
- 29TOC scheduling; non-drumany resource whose capacity is more than the demand
- 30TOC scheduling; roperefers to pull scheduling at the non bottleneck work centers. move material as quickly as possible through non bottleneck work centers until it reaches the bottleneck. the work at the bottleneck is scheduled for maximum efficiency
- 31Issue TOC-assumption of certainty of the processing times.
- whenever one job is completed, another is ready to go on the bottleneck machine
- a safety stock of nonbottleneck operation completed parts is held before final assembly
- TOC scheduling system to reduce the effect of uncertainty - 32Managing TOC schedule- scheduling the drum: scheduling new orders on the bottleneck operations
- exploiting the drums: product demand may exceed the available capacity at the drums
- material release- rope: raw materials should not be released earlier than the scheduled TOC raw material release date
- evaluating the drum: once the shop floor is running smoothly, consideration should be given in the planning process to increasing the capacity at the drum - 335 focusing steps (POOGI)1. identify (identify the current constraint)
2. exploit (make quick improvements to the throughput of the constraint with existing resources)
3. subordinate (review all other activities and align with and support the need of the constraint)
4. elevate ( consider what further actions can be taken to eliminate the constraint, maybe capital investment)
5. repeat ( find next constraint)
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- Flashcards on Production lecture 4, created by Elisa Vink on 04/10/2020.
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- Elisa Vink
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