Contents. The Planning Hierarchy. Capacity / Load. TPPE37 Manufacturing Control

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1 TPPE37 Manufacturing Control Contents Lecture 6 Capacity Planning Capacity theory RoughCut Capacity Planning Three different techniques Comparison of of the the techniques Capacity Requeriments Planning (CRP) Manufacturing Resource Planning (MRPII) Capacity theory, RCCP, CRP, MRPII 1 Capacity theory, RCCP, CRP, MRPII 2 The Planning Hierarchy Capacity / Load Master planning Demand management Feedback Final assembly schedule Vendor systems Sales and operations planning Production planning Master prod. schedule Material planning Shop floor systems Resource planning Master (production) scheduling Roughcut capacity plan Detailed capacity planning Front end Engine Back end Capacity: The capability of ofa resource to to produce output per time period Load: The amount of of planned work scheduled for for and actual work released to toa resource for for a specific time Capacity utilization Load/Capacity Capacity theory, RCCP, CRP, MRPII 3 Capacity theory, RCCP, CRP, MRPII 4

2 Traditional definition of capacity Capacity definitions (1) C = T E U ( L ) C= Calculated capacity T= Theoretical capacity E= Efficiency factor U= Utilization factor L= Load Efficiency = a ameasure of of how how closely predetermined standards are are achieved Utilisation = a ameasure of of how how intensely a resource is isbeing used Capacity theory, RCCP, CRP, MRPII 5 Theoretical capacity Based on on clock hours Example: 4 machines 8 hrs/day 5 days/week = 16 16hrs/week.2.2 standard hours/pcs 16/.2 = 8 8pcs/week Theoretical capacity (T)= (T)= 8 8pcs/week or or16 16hrs/week Calculated capacity, Planned capacity Theoretical capacity adjusted for forutilization and andefficiency Example: 16 16theoretical hrs/week 9% 9% util. util. 8% 8% eff. eff. = 1.2 hrs/week.2.2 standard hours/pcs 1.2/.2 = pcs/week Calculated capacity (C) (C) = pcs/week or or1.2 hrs/week Capacity theory, RCCP, CRP, MRPII 6 Capacity definitions (2) Load / Queues Demonstrated capacity Based on on historical averages over over the the previous periods Example: The Thelast lastsix sixperiods production: = 58, 58, 565, 565, 575, 575, 57, 57, 59, 59, Average production = pcs/week.2.2 standard hours/pcs = hrs/week Demonstrated capacity = pcs/week or or114.6 hrs/week Queue (length/time) Maximum capacity The Themaximum possible capacity a system can can provide without further investments 1% Load Capacity theory, RCCP, CRP, MRPII 7 Capacity theory, RCCP, CRP, MRPII 8

3 RoughCut Capacity Planning Techniques for RCCP Better name: RoughCut Load Estimation Rough estimation of of future loads of of the resources Most common in inbatch manufacturing (classical RCCP) which is is a dynamic and information intensive environment InOnetime manufacturing is iseach order given a detailed schedule from the thestart which makes RCCP superfluous InFlow manufacturing the the environment is isstatic and a detailed analysis is iscarried out for foreach change Estimation whether more capacity, less capacity or or load leveling is isnecessary for for a better fit fit between capacity and load. Three different techniques: Capacity Planning Using Overall Factors Capacity Bills, Bill Billof of Resources Resource Profiles Capacity theory, RCCP, CRP, MRPII 9 Capacity theory, RCCP, CRP, MRPII 1 Ex: RCCP Capacity Planning Using Overall Factors A company has two end products, A och B, B, that are manufactured in inthree critical resources,, WC2 and WC Work Center Capacity (hours per period) 36 (= ) WC2 38 (= ) WC 2 (= ) Period MPS: A MPS: B Information required: Master Production Schedule Resources demanded (end (end items) Historical load load of of resources Assumptions: The The historical level level will will continue The Thesame sameproduct mix mix Capacity theory, RCCP, CRP, MRPII 11 Capacity theory, RCCP, CRP, MRPII 12

4 Ex: CPOF (1) Ex: CPOF (2) Product Standard time / item A.95 hours B 1.85 hours Quarter 1 Quarter 2 Quarter 3 Quarter 4 Total Historical percentage ,3 % WC ,4 % WC ,3 % Week Total (%) : A : B : A+B WC2: A WC2: B WC2: A+B WC: A WC: B WC: A+B (6.3) (.4) (9.3) Total (1) Capacity theory, RCCP, CRP, MRPII 13 Capacity theory, RCCP, CRP, MRPII 14 Capacity bills Ex: Capacity bills (1) Information required: Master Production Schedule Capacity bills bills Resources demanded (end (end items itemsand andcomponents) Bill Billof ofmaterial, BOM BOM Assumption: The The historical level level continues. Independent of of time time phasing. Standard lot lot sizes. Capacity theory, RCCP, CRP, MRPII Product Lot size Work center Setup time [hrs/batch] Setup [hrs/pcs] Oper. time [hrs/pcs] Total [hrs/pcs] A B C 4 WC2 WC D 6 WC E 1 WC F 1 WC Bill of capacity: Work center A [hrs/pcs] B [hrs/pcs].5 1. WC WC.2. Total [hrs/pcs] Capacity theory, RCCP, CRP, MRPII 16

5 Ex: Capacity bills (2) Resource Profiles Week Total (%) : A : B : A+B WC2: A WC2: B WC2: A+B WC: A WC: B WC: A+B (39.9) (5.3) (9.8) Total (1.) Information required: Master Production Schedule Resources demanded (end (end items and andcomponents) Bill Billof ofmaterial, BOM Lead Lead time timeoffsets Assumption: Standard lot lot size size Capacity theory, RCCP, CRP, MRPII 17 Capacity theory, RCCP, CRP, MRPII 18 Ex: Resource Profiles (1) Ex: Resource Profiles (2) Resources required Standard time/item and and period Product Work center 2 1 A B WC2 WC WC Capacity theory, RCCP, CRP, MRPII 19 Week Total (%) :A :B :A+B WC2:A1* WC2:A2* WC2:B1* WC2:B2* WC2:A+B WC:A WC:B WC:A+B (39.9) (5.3) 5 (9.8) Total (1.) * A1,B1 A1,B1 och och A2,B2: A2,B2: Capacity required requiredfor for order ordertoto be bedelivered in in 1 or or2 periods. periods. These These are are assumed to tobe be in in process, process, if ifnot notthey they are are (past (past due) due) and and must must be beadded to to the theplan for for period period 1 and and forward forward Capacity theory, RCCP, CRP, MRPII 2

6 Ex: Comparison of results Summary (1) Work center WC2 Week Total CPOF (4) Capacity bills (4) Resource prof (4) 6 4 CPOF Capacity bills 2 Resource profiles Capacity theory, RCCP, CRP, MRPII 21 Capacity Planning Using Overall Factors, CPOF Advantages + Small amount of ofdata dataneeded + Simple calculations Disadvantages Valid only onlyas aslong longas asthe historical percentage is isapplicable Based on on historical production No Noexplicit relation between end end items produced and andhow the the items are are manufactured and andresourcesare required (e.g. (e.g. via via BOM) No Nolead time timeoffsetting which is isnecessary when demand varies Capacity theory, RCCP, CRP, MRPII 22 Summary (2) Summary (3) Capacity Bills Advantages + Better coupling between enditems and andresource requirements + Simple + Valid also also when the the product mix mixchanges Disadvantages Requires detailed data dataconcerning BOM and androuting (setup and and operation times) No Nolead time timeoffsetting which is isnecessary when demand varies The The setup time timeisis allocated based on onstandard lot lot sizes sizes (could be be misleading if if dynamic lot lot sizing is isused) Capacity theory, RCCP, CRP, MRPII 23 Resource profiles Advantages + Better coupling between enditems and andresource requirements + Lead Lead time timeoffsetting which is isnecessary when demand varies + Valid also also when the the product mix mixchanges Disadvantages Requires detailed data dataconcerning BOM and androuting (setup and and operation times) The The setup time timeisisallocated based on onstandard lot lot sizes sizes (could be bemisleading if if dynamic lot lot sizing is isused) Capacity theory, RCCP, CRP, MRPII 24

7 Resource planning, RP Ex: Resource planning A weighted sum of of resources required according to torccp Work center A [hrs/pcs] B [hrs/pcs] AB [hrs/pcs] WC WC.2..7 Total [hrs/pcs] Capacity theory, RCCP, CRP, MRPII Capacity theory, RCCP, CRP, MRPII 26 Capacity requirements planning What is the timing of load? Information about planned order from the thempc system Info. about released orders from manufacturing (and from purchasing in insome cases) Deterministic simulation based on on released and planned orders Load reports (CRP reports) are the the outputs Estimated load is iscompared to to available capacity RoughCut Capacity Planning (RCCP) Focuses on on average load load (over the the planning horizon) Capacity Requirements Planning (CRP) Focuses usually on on cumulate load load (by (by period) Capacity theory, RCCP, CRP, MRPII 27 Order start and order due date are set setbut when are the the individual operations performed? Forward scheduling Based on onorder start Back scheduling Based on on due dates Capacity theory, RCCP, CRP, MRPII 28

8 Example: CRP Ex: Material data Time phased manufacturing MRPbased MPC system one enditem, three work centers Planning principle: One operation per week Planning horizon is is 12 weeks but only 7 weeks are included in inthe matrices Todays date: Friday /6 Level Item Antal per moderartikel Beskrivning 1 1 End item Sub assembly Component A Component B Item no. Lot sizing On hand invent Sched. receip. Lead time Allocations [Weeks] 1 LFL (3/7) 1 11 FOQ = (1/7) FOQ = (1/7) FOQ = (1/7) 4 Capacity theory, RCCP, CRP, MRPII 29 Capacity theory, RCCP, CRP, MRPII Ex: Operation data and MPS Ex: Routing Work center Available time [min/week] Utilization Efficiency Planned queue [days] 24 (= 5 8 6) 1% 1% 4 WC2 24 1% 1% 4 WC3 24 1% 1% 4 W eek MPS Item Work center Setup time [min/batch] Operation time [min/unit] WC2 121 WC3 WC2 122 WC2 WC3 WC Capacity theory, RCCP, CRP, MRPII 31 Capacity theory, RCCP, CRP, MRPII 32

9 Ex: Material flows Ex: RCCP Capacity Bills Week Average load WC WC WC2 WC Avera. Capacity theory, RCCP, CRP, MRPII 33 Capacity theory, RCCP, CRP, MRPII 34 Ex: MRPcalculation (1) Item no: 1 Description: End item Lead time: 1 week Buffer: Lot sizing: LFL Period Gross requirements 2 2 Scheduled receipts Inventory position Net requirements 2 2 Net req. consid. planned orders 2 2 Planned order receipts 2 2 Projected available balance Planned order releases 2 2 Item no: 11 Description: Sub assembly Lead time: 2 weeks Buffer: Lot sizing: FOQ=4 Period Gross requirements (2*1) Scheduled receipts 4 Inventory position Net requirements 4 5 Net req. consid. planned orders 5 4 Planned order receipts Projected available balance Planned order releases Ex: MRPcalculations (2) Item no: 121 Description: Component A Lead time: 3 weeks Buffer: Lot sizing: FOQ=24 Period Gross requirements (3*11) Scheduled receipts 24 Inventory position Net requirements Net req. consid. planned orders Planned order receipts Projected available balance Planned order releases Item no: 122 Description: Component B Lead time: 4 weeks Buffer: Lot sizing: FOQ= Period Gross requirements (5*11) Scheduled receipts Inventory position Net requirements Net req. consid. planned orders 2 Planned order receipts Projected available balance Planned order releases Capacity theory, RCCP, CRP, MRPII 35 Capacity theory, RCCP, CRP, MRPII 36

10 Ex: Setup matrix (planned orders) Ex: Op. time matrix (planned orders) WC WC Item Total Total Total 45 Capacity theory, RCCP, CRP, MRPII WC WC Item Total Total Total Capacity theory, RCCP, CRP, MRPII 38 Ex: Capacity req. for planned orders Ex: Capacity req. for released orders Setup time + Operation time Week Average load WC WC Remaining operations for forreleased orders (Sched. receipts.). This information is isobtained from the thempc system. Item Work center Week Setup time Operation time Total time = WC2 121 WC2 122 WC = 4.5 = = 24. =.5 =.35 = Capacity theory, RCCP, CRP, MRPII 39 Capacity theory, RCCP, CRP, MRPII 4

11 Ex: Total capacity req. acc. to CRP Ex: CRP Load report Week Average load WC WC Work center 2 Cum. dev Avera. WC2 WC3 Week Capaciy [min.] Load [min.] Utilization [%] Deviation [min.] Cumulative dev. [min.] Capacity theory, RCCP, CRP, MRPII 41 Capacity theory, RCCP, CRP, MRPII 42 Ex: Result of setup reduction 1 Ex: Result of setup reduction 2 5% reduction of of setup times Lot sizing: According to tolfl Week Average load WC WC Item no. Previous lot sizing New lot sizing 1 LFL LFL 11 FOQ (4) LFL 121 FOQ (24) LFL 122 FOQ () LFL Avera. WC2 WC3 Capacity theory, RCCP, CRP, MRPII 43 Capacity theory, RCCP, CRP, MRPII 44

12 Ex: Result of setup reduction 3 Definitions of MRPconcepts 5 1 Work center 2 Cum. dev. 1 Week Capacity [min.] Load [min.] Utilization [%] Deviation [min.] Cumulative dev. [min.] Capacity theory, RCCP, CRP, MRPII 45 MRP, also MRP I, I, mrp or or little MRP: Material requirements system based on on the the net net requiement calculations Closed loop MRP: MPS + RCCP + MRP + CRP + feedback (PAC) MRPII: Manufacturing resource planning concerns all all the the resources of of the the company and also generates output in in terms of of financial consequences of ofall decisions. Capacity theory, RCCP, CRP, MRPII 46 Closedloop MRP system Capacity theory, RCCP, CRP, MRPII 47