생산운영관리 총괄계획 (APP) (Ch. 13) & 자재소요계획 (MRP) (Ch. 14) Hansoo Kim ( ) Dept. of Management Information Systems, YUST 1 Schedule! 12/7 APP & MRP! 12/14 ERP & Review! 12/21 2 nd Exam Final Exam 2
OM Overview Class Overview (Ch. 0) Operations, Productivity, and Strategy (Ch. 1, 2) Project Management (Ch. 17) Strategic Capacity Planning (Ch. 5, 5S) Process Selection/ Facility Layout; LP (Ch. 6, 6S) X X X X X X Mgmt of Quality/ Six Sigma Quality (Ch. 9, 10) X Queueing/ Simulation (Ch. 18) X Supply Chain Management (Ch 11) Location X X Planning JIT & and Analysis Lean Mfg System (Ch. 8) (Ch. 15) X Demand Mgmt Forecasting (Ch 3) Aggregated Planning (Ch. 13) X Inventory Management (Ch. 12) MRP & ERP (Ch 14) Term Project 3 Today s Outline! (APP)..! (MRP).. 4
계획수립단계 5? Month Expected Demand Production Days Demand per Day Jan. Feb. 900 700 22 18 41 39 Mar. 800 21 38 Apr. May. 1,200 1,500 21 22 57 68 Jun. 1,100 20 55 Total 6,200 124 Inventory Carrying Cost ( ) Subcontracting cost per unit ( ) Average pay rate ( ) Over time pay rate ( ) Labor-hours to produce a unit ( ) Cost of increasing production rate ( ) Cost of decreasing daily production rate ( ) $ 5 per unit per month $ 10 per unit $ 40 per day $ 7 per hour (above 8hrs per day) 1.6 hr per unit $300 per unit $600 per unit 6
: No Change Workforce!. No change workforce (No Hire No Layoffs)!. No Overtime or No subcontract!. Use inventory! 7 Production rate per working day 70 60 50 40 30 20 10 6200/124'='50' Forecast Demand 0 Jan Feb Mar Apr May Jun 22 18 21 21 22 20 8
using Excel Costs (per unit) Reg time 8 Overtime 11.2 Subcontract 10 Holding 5 P rate 50 per day Working Days P rate /m 22 1100 18 900 21 1050 21 1050 22 1100 20 1000 6200 Data Period Demand Reg Time Production Overtime Production Subcontract Production Jan 900 1100 0 Feb 700 900 0 Mar 800 1050 0 Apr 1200 1050 0 May 1500 1100 0 Jun 1100 1000 0 Total 6200 6200 0 0 Average 1033.333 Cost $49,600 $0 $0 Total Cost $58,850 Inventory Holding 200 200 400 400 650 650 500 500 100 100 0 0 1850 7216 $9,250 Inventory Carrying Cost ( 재고보관비 )= $ 5 per unit per month 9 :,! (3, 38 / ),! (Subcontract). 10
Using Excel Costs (per unit) Reg time 8 :=1.6*5 Overtime 11.2 Subcontract 10 Holding 5 Shortage Increase 0 Decrease 0 Starting Conditions Initial inventory 0 Units last period 38unit/day 38 Data Period Demand Reg Time Production Overtime Production Subcontract Production Jan 900 836 0 64 Feb 700 684 0 16 Mar 800 798 0 2 Apr 1200 798 0 402 May 1500 836 0 664 Jun 1100 760 0 340 Total 6200 4712 0 1488 Average 1033.333 Cost $37,696 $0 $14,880 Total Cost $52,576 11 : Month` Expected De mand Demand per Day Production Cost Hire Cost ($300/unit) Layoff Cost ($600/unit) Total Cost Jan. Feb. Mar. Apr. May. Jun. 900 700 800 1,200 1,500 1,100 41 39 38 57 68 55 $7200 5600 6400 9600 12000 8800 - - - $5700 $3300 - - $1200 $600 - - $7800 $7200 6800 7000 15300 15300 16600 Total 6,200 $49600 $9000 $9600 $68200 12
Planning Horizon Short-range plans Job assignments Ordering Job scheduling Dispatching Responsible: Operations managers, supervisors, foremen Responsible: Operations managers Intermediate-range plans Sales planning Production planning and budgeting Setting employment, inventory, subcontracting levels Analyzing operating plans Responsible: Top executives Long-range plans R&D New product plans Capital expenses Facility location, expansion Today 3 Months 1 year 5 years Planning Horizon 13 (AP)!. " Logical overall unit for measuring sales and outputs! (aggregated). " Forecast of demand for intermediate planning period in these aggre gate units!. " Method for determining costs!,. " Model that combines forecasts and costs so that planning decisions can be made 14
Marketplace and Demand Product Decisions Research and Technology Demand Forecasts, orders Process Planning & Capacity Decisions Aggregate Plan for Production Master Production Schedule, and MRP systems Work Force Raw Materials Available External Capacity Subcontractors Inventory On Hand Detailed Work Schedules 15 APP, or AP (Aggregate Production Planning)! " Matches market demand to company resources! 3 12 " Plans production 3 months to 12 months in advance!, " Combines ( aggregates ) production!, (demand) (Resources), (capacit y). " Expresses demand, resources, and capacity in general terms!. " Develops a strategy for economically meeting demand!. " Establishes a company-wide game plan for allocating resources 16
AP! " Meet demand! " Use capacity efficiently! " Meet inventory policy! " Minimize cost! (Labor cost)! (Inventory)! (Plant & equipment)! (Subcontract) 17 AP : (Pure Strategy)! Capacity Options change capacity: ", changing inventory levels " /, varying work force size by hiring or layoffs ", varying production capacity through overtime or idle time ", subcontracting ", using part-time workers 18
AP : (Pure Strategy)!, Demand Options change demand: ", influencing demand " (Back-order), backordering during high demand periods ", counter-seasonal product mixing 19 Level Strategy Chase Strategy 20
AP!, Mixed strategy " 2 AP Combines 2 or more aggregate scheduling options!, Level scheduling strategy ", Produce same amount every day ", Keep work force level constant ", Vary non-work force capacity or demand options ", Often results in lowest production costs 21 예제 1! 여러스케이트보드모델을생산하는회사의계획수립자들이여섯기간동안의총괄계획을수립하고자한다. 그들은다음과같은정보를수집했다. 기간 1 2 3 4 5 6 총계 예측치 200 200 300 400 500 200 1,800 비용 산출 = 스케이트보드당 $2 정규시간 = 스케이트보드당 $3 초과근무시간 = 스케이트보드당 $6 하도급 = 스케이트보드당 $1( 평균재고에대해 1 기간당 ) 재고 = 스케이트보드당재고 $5(1 (Inventory) 기간당 ) 백로그 ( 백오더 ) 백오더 초과근무 (Overtime) 하도급 (Subcontract) 정규시간 22 (Regular'Time)
예제 1 해답 (1/2) 기간 1 2 3 4 5 6 총계 예측치 200 200 300 400 500 200 1,800 산출 정규시간 초과근무시간 300 300 300 300 300 300 1,800 --- --- --- --- --- --- --- 하도급 --- --- --- --- --- --- --- 산출 - 예측치 100 100 0 (100) (200) 100 0 재고 초기 0 100 200 200 100 0 기말 100 200 200 100 0 0 평균 50 150 200 150 50 0 600 백로그 0 0 0 0 100 0 100 23 예제 1 해답 (2/2) 비용 1 2 3 4 5 6 총계 산출 정규초과근무하도급채용 / 해고 $600 600 600 600 600 600 43,600 재고 $50 150 200 150 50 0 $600 백오더 $0 0 0 0 500 0 $500 총계 $650 750 800 750 1,150 600 $4,700 24
예제 2! 25 2 (1/2) 기간 1 2 3 4 5 6 총계 예측치 200 200 300 400 500 200 1,800 산출 정규시간 초과근무시간 280 280 280 280 280 280 1,680 0 0 40 40 40 0 120 하도급 --- --- --- --- --- --- --- 산출 - 예측치 80 80 20 (80) (180) 80 0 재고 초기 0 80 160 180 100 0 기말 80 160 180 100 0 0 평균 40 120 170 140 50 0 520 백로그 0 0 0 0 80 0 80 26
예제 1 해답 (2/2) 비용 1 2 3 4 5 6 총계 산출 정규초과근무하도급채용 / 해고 $560 560 560 560 560 560 $3,360 0 0 120 120 120 0 $360 재고 $40 120 170 140 50 0 $520 백오더 총계 $0 0 0 0 400 0 $400 $600 680 850 820 1,130 560 $4,640 27 AP Using Mixed Strategies MONTH DEMAND (CASES) MONTH DEMAND (CASES) January 1000 July 500 February 400 August 500 March 400 September 1000 April 400 October 1500 May 400 November 2500 June 400 December 3000 Production per employee = 100 cases per month Wage rate = $10 per case for regular production = $15 per case for overtime = $25 for subcontracting Hiring cost = $100 per worker Firing cost = $500 per worker Inventory carrying cost = $1.00 case per month Beginning work force = 10 workers 28
AP by Linear Programming Subject to where H t = # hired for period t F t = # fired for period t I t = inventory at end of period t P t = units produced in period t W t = workforce size for period t Minimize Z = $100 (H 1 + H 2 + H 3 + H 4 ) + $500 (F 1 + F 2 + F 3 + F 4 ) + $0.50 (I 1 + I 2 + I 3 + I 4 ) P 1 - I 1 = 80,000 (1) Demand I 1 + P 2 - I 2 = 50,000 (2) constraints I 2 + P 3 - I 3 = 120,000 (3) I 3 + P 4 - I 4 = 150,000 (4) Production 1000 W 1 = P 1 (5) constraints 1000 W 2 = P 2 (6) 1000 W 3 = P 3 (7) 1000 W 4 = P 4 (8) 100 + H 1 - F 1 = W 1 (9) Work force W 1 + H 2 - F 2 = W 2 (10) constraints W 2 + H 3 - F 3 = W 3 (11) W 3 + H 4 - F 4 = W 4 (12) 29 주일정계획 (Master Schedule): 계획기간동안의개별최종제품의수량과생산시기를나타내는계획 총괄계획월 Jan. Feb. Mar. (** 총괄수량 ) 계획된산출 ** 200 300 400 주일정계획월 Jan. Feb. Mar. 계획된산출 * 미는형 100 100 100 자동형 75 150 200 탑승형 25 50 100 총계 200 300 400 그림 13.4 총괄계획에서주일정계획으로이동 (* 실제모델별수량 ) 30
(Master Scheduling) 투입물 ' 산출물 ' 초기재고 수요예측치 고객주문 주일정계획 ( 최종수량, 시기 ) 예상재고 기준생산계획 (MPS) 미계약재고 약속가능재고 '' 31 MPS & RCCP! 기준생산계획 (Master'production'schedule;'MPS)'! 개략적 ' 생산용량 ' 계획 ' (Rough-cut'capacity'planning;'RCCP)'' 32
-> MPS (1/5) 6 월 7 월 1 2 3 4 5 6 7 8 예측치 30 30 30 30 40 40 40 40 그림 13.8 A 산업용펌프에대한주별예측소요량 초기재고 ---64 6 월 7 월 1 2 3 4 5 6 7 8 예측치 30 30 30 30 40 40 40 40 고객주문 ( 약속된 ) 33 20 10 4 2 그림 13.8 B 예상치, 고객주문그리고초기재고를표시하는 8 주스케줄 33 -> MPS (2/5) 6월 7월 초기재고---64 1 2 3 4 5 6 7 8 예측치 30 30 30 30 40 40 40 40 고객주문 ( 약속된 ) 33 20 10 4 2 예상보유재고 31 1-29 그림 '13.9' 34
-> MPS (3/5) 주 이전주로 부터의재고 소요량 * MPS 이전의 순재고 (Lot Size = 70) 순재고 예상재고 1 64 33 31 31 2 31 30 1 1 3 1 30-29 + 70 = 41 4 41 30 11 11 5 11 40-29 + 70 = 41 6 41 40 1 1 7 그림 '13.10' 1 40-39 + Lot'Size'70 = 31 인 ' 경우 ' 8 31 40-9 + 70 = 61 35 ( * ) -> MPS (4/5) 6월 7월 64 1 2 3 4 5 6 7 8 예측치 30 30 30 30 40 40 40 40 고객주문 ( 약속된 ) 33 20 10 4 2 예상보유재고 31 1 41 11 41 1 31 61 기준생산계획 (MPS) 70 70 70 70 그림 '13.11' 36
-> MPS (5/5) 64 6월 7월 1 2 3 4 5 6 7 8 예측치 30 30 30 30 40 40 40 40 고객주문 ( 약속된 ) 33 20 10 4 2 예상보유재고 31 1 41 11 41 1 31 61 기준생산계획 70 70 70 70 그림 ATP '13.12' 재고 ( 약속되지않은 ) 11 56 68 70 70 37 (1/2)! 목적 '! 목표 '! 가능한 전략들 ' 38
(2/2)! 총괄계획 ' 수립의 ' 관리적 ' 중요성 ' 39 MRP Material Requirement Planning 40
Marketplace and Demand Product Decisions Research and Technology Demand Forecasts, orders Process Planning & Capacity Decisions Aggregate Plan for Production Master Production Schedule, and MRP systems Work Force Raw Materials Available External Capacity Subcontractors Inventory On Hand Detailed Work Schedules 41 Change requirements? Aggregate production plan Master production schedule (MPS) Material Requirements Plan Change production plan? Change master production schedule? Change capacity? No Detail capacity plan Realistic Yes Execute capacity plans Is capacity plan being met? Is execution meeting the plan? Execute material plans 42
AP->MPS Months January February Aggregate Production Plan (shows the total quantity of amplif iers) 1,500 1,200 Weeks 1 2 3 4 5 6 7 8 Master Production Schedule (Shows the specific type and quan tity of amplifier to be produced) 240 watt amplifier 100 100 100 100 150 watt amplifier 500 500 450 450 75 watt amplifier 300 100 43 Material Requirements Planning (MRP)!,! Manufacturing computer information system! Determines quantity & timing of dependent demand items 1 2 3 4 5 Gross Requirements 2 20 25 15 Scheduled Receipts 5 30 Available 25 23 33 33 8 Net Requirements 7 Planned Order Receipts 7 Planned Order Releases 7 44
MRP! Computer system! Mainly discrete products! Accurate bill-of-material! Accurate inventory status " 99% inventory accuracy!, Stable lead times 1984-1994 T/Maker Co. 45 주문 ' 예측치 ' MRP투입물 ' MRP처리 ' MRP산출물 ' 변경사항 ' 발주 ' 주일정계획 ' 계획주문 ' 일정 ' 실제변경 ' 자재명세서 ' MRP 컴퓨터프로그램 ' 예외보고서 ' 계획보고서 ' 입고 ' 출고 ' 재고기록 ' 성과관리보고서 ' 그림 '14.2' MRP 개요 ' 재고처리 '
MRP! " Increased customer satisfaction due to meeting delivery schedules! " Faster response to market changes! / " Improved labor & equipment utilization! " Better inventory planning & scheduling!, " Reduced inventory levels without reduced customer service 47 Bill-of-Material (BOM)!! Tree " Parents:! Items above given level " Children:! Items below given level! " (Low-Level- Coding)!, 48
조립도 ' 의자 ' 제품구조나무 ' 완성된 ' 의자 ' 다리조립품 ' 좌석 ' 등판조립품 ' 앞쪽다리 ' 등받침 ' 다리 (2)' 연결대 ' 다리 (2)' 연결대 ' 등받침 ' 연결대 ' 뒤쪽다리 ' 연결대 ' 그림 14.5' 의자 ' 조립품의 ' 조립도와 ' 제품구조나무 ' 예제 1 A) X B,C,D,E,F B)10 X B 4 C 10 D 8 E 60 50
X' B:'2*1'='2' B(2)' C:'1*1'='1' C' D:'3*2'='6' D(3)' E:'1*2'='2' E' E:'2*1'='2' E(2)' F:'2*1'='2' F' E:'4*6'='24' E(24)' 따라서 ' 하나의 'X 는 ' B:'2''''' C:'1' D:'6' E:28( 주의 :'E 는 ' 세곳에서 ' 발생하며 ' 소요량은 '24+2+2=28)' F:2'' ) BOM for Awesome A 52
Time-Phased Product Structure Start production of D 2 weeks 1 week G D 2 weeks Must have D and E completed here so production can begin on B 1 week 3 weeks 2 weeks E 1 week 1 2 3 4 5 6 7 8 D E 2 weeks to produce F B 1 week C A 53 ) BOM for Stool ( ) Indented BOM Graphical BOM Stool Base (1) Legs (4) Bolts (2) Seat (1) Bolts (2) Base (1) Stool Seat (1) Level 0 Level 1 Legs (4) Bolts (4) Bolts (2) Level 2 Note: bolts are treated at lowest level in which they occur for MRP calcs. Actually, they might be left off BOM altogether in practice. ( 하위수준코딩 ) 54
) MRP (1/2) Item: Stool (Leadtime = 1 week) Week 0 1 2 3 4 5 6 총소요량 120 예정입고량예상보유량 20 20 20 20 20-100 -100 순소요량 100 계획입고량 100 Item: Base (Leadtime = 1 week) Week 0 1 2 3 4 5 6 총소요량 100 예정입고량예상보유량 0 0 0 0-100 -100-100 순소요량 100 계획입고량 100 55 ) MRP (2/2) Item: Legs (Leadtime = 2 weeks) BOM explosion Week 0 1 2 3 4 5 6 총소요량 400 예정입고량 200 예상보유량 0 0 200-200 -200-200 -200 순소요량 200 계획입고량 200 56
BOM for Awesome A 57 Gross Material Requirements Plan for 50 Awesome A Speaker Kits 58
Derivation of Master Schedule A S Periods B Lead time = 4 for A Master schedule for A C 5 6 7 8 9 10 11 40 50 15 B C Lead time = 6 for S Master schedule for S 8 9 10 11 12 13 40 20 30 Master schedule for B sold directly 1 2 3 10 10 Periods Gross requirements: B 1 2 3 4 5 6 7 8 10 40+10 = 50 40 50 20 15+30 = 45 Therefore, these are the gross requirements for B 59 Lot-Sizing Techniques 로트크기결정 : 주문혹은생산을위한로트크기의선택! Lot-for-lot (, L4L)! Economic Order Quantity ( )! Part Period Balancing ( )! Fixed Order Period ( ) 60
MRP Lot-Sizing Problem: Lot-for-Lot Techn iques Total Cost = 100 * 7 = $700 61 MRP Lot-Sizing Problem: EOQ Techniqu e Total Cost 10 = 2DhS 52 10 = 2 (27 52) (1 52) 100 52 $735 62
Part Period Balancing Tech. Calculation! Holding Cost = $1/unit,week, Setup Cost = $100, Lead Time = 1 week! Economic Part Period (EPP) = Setup Cost Holding Cost = 100/1 = 100 unit Demand 1 2 3 4 5 6 7 8 9 10 35 30 40 0 10 40 30 0 30 55 Periods Combined Cumulative Net Reqmt Part Period Cost Setup Holding Total 2 2,3 2,3,4 2,3,4,5 2,3,4,5,6 -------- 6 6,7 6,7,8 6,7,8,9 -------- 10 30 70 70 80 120 ---- 40 70 70 100 ---- 55 0 40 = 40*1 40 70 = 40*1 + 10*3 230 = 40*1 + 10*3 + 40*4 ------------------- 0 30 = 30*1 30 = 30*1+0*2 120 = 30*1 + 30*3 ------------------- 0 100 --- 100 --- 100 70 -- 120 -- 0 170 --- 220 --- 100 63 300 190 $490 MRP Lot-Sizing Problem: PPB Techniqu e 64
Fixed Order Period (FOP): 3 periods 1 2 3 4 5 6 7 8 9 10 Gross Req. 35 30 40 0 10 40 30 0 30 55 Sched. Recei pt Projt on Han d (35) 35 0 40 0 0 40 30 0 0 55 Net Requirem ent. 0 30 0 0 10 0 0 0 30 0 Planed order Receipt 0 70 =30+ 40+0 0 0 80 0 0 0 85 0 Planed Order Release Holding Cost = $1/unit week, Setup Cost = $100 Lead Time = 1week 70 0 0 80 0 0 0 85 0 0 Total Cost = 100*3 + 40*1 + 40*1 + 30*2 + 55 = $495 65 Total Cost Comparison Total cost comparison by Lot sizing Techni ques! L4L = $700! EOQ = $735! PPB = $490 **! FOP = $495 66
MRP and ERP Information Flows, Integr ated with Other Systems 67 Announcement! HW " Ch.14! Example 1, 2! Solved Problem 1, 2 " Ch. 13! Example 1, 2! ERP & Review 68