mgs4700 operations management - georgia state universitydscgpz/mgs4700/chap15.pdf · resource...

Resource Planning

MGS4700 Operations Management

Lecture 11

___________________________________

___________________________________

___________________________________

___________________________________

___________________________________

___________________________________

___________________________________

2

Lecture Outline

Material Requirements Planning (MRP)

Capacity Requirements Planning (CRP)

___________________________________

___________________________________

___________________________________

___________________________________

___________________________________

___________________________________

___________________________________

3

Resource Planning for Manufacturing

___________________________________

___________________________________

___________________________________

___________________________________

___________________________________

___________________________________

___________________________________

4

Material RequirementsPlanning (MRP)

MRP is a computer-based production planning system that specifies what, how much, and when materials (parts) are needed to produce end itemsWhen to Use MRP

Dependent demandDiscrete demandJob shop productionAssemble-to-order environments

___________________________________

___________________________________

___________________________________

___________________________________

___________________________________

___________________________________

___________________________________

5

Demand Characteristics

1 2 3 4 5Week

400 –

300 –

200 –

100 –No.

of t

able

s

Continuous demand

M T W Th F M T W Th F

400 –

300 –

200 –

100 –No.

of t

able

s

Discrete demand

Independent demand

100 tables

Dependent demand

100 x 1 = 100 tabletops

100 x 4 = 400 table legs

___________________________________

___________________________________

___________________________________

___________________________________

___________________________________

___________________________________

___________________________________

6

MRP: Inputs & Outputs

Materialrequirements

planning

Planned order

releases

Work orders

Purchase orders

Rescheduling notices

Itemmaster

file

Productstructure

file

Master production schedule

___________________________________

___________________________________

___________________________________

___________________________________

___________________________________

___________________________________

___________________________________

7

Inputs to MRP

Master Production ScheduleMaster Production Schedule (MPS)-- a schedule specifying how many and when each end item should be produced

PERIODMPS ITEM 1 2 3 4 5

Clipboard 85 95 120 100 100Lapdesk 0 50 0 50 0Lapboard 75 120 47 20 17Pencil Case 125 125 125 125 125

___________________________________

___________________________________

___________________________________

___________________________________

___________________________________

___________________________________

___________________________________

8

Inputs to MRP

Product Structure FileBill of Materials (BOM)/Product Structure Tree

A complete list of all components and the sequence to make the product

Indented BOM for Item A

Item Number RequiredA 1 B 2 D 2 E 3 C 3 E 2 F 1 D 2 G 1

Product Structure Tree for Item A

A

B(2) C(3)

D(2) E(3)

G(1) D(2)

E(2)F(1)

___________________________________

___________________________________

___________________________________

___________________________________

___________________________________

___________________________________

___________________________________

9

Product Structure Example

Top clip (1) Bottom clip (1)

Pivot (1) Spring (1)

Rivets (2)Finished clipboard Pressboard (1)

Clipboard

___________________________________

___________________________________

___________________________________

___________________________________

___________________________________

___________________________________

___________________________________

10

Product Structure Tree

Clipboard Level 0

Level 1

Level 2Spring (1)

Bottom Clip (1)

Top Clip (1)

Pivot (1)

Rivets (2)

Clip Ass’y (1)

Pressboard (1)

___________________________________

___________________________________

___________________________________

___________________________________

___________________________________

___________________________________

___________________________________

11

Inputs to MRP

Item Master File

Also called inventory Records FileA database containing information on every item produced, ordered, or inventoried

On-hand inventoryOrders outstandingLead timeInventory policyEtc.

___________________________________

___________________________________

___________________________________

___________________________________

___________________________________

___________________________________

___________________________________

12

Item Master File ExampleDESCRIPTION INVENTORY POLICY

Item Pressboard Lead time 1Item no. 734 Annual demand 5000Item type Purch Holding cost 1Product/sales class Comp Ordering/setup cost 50Value class B Safety stock 0Buyer/planner RSR Reorder point 39Vendor/drawing 07142 EOQ 316Phantom code N Minimum order qty 100Unit price/cost 1.25 Maximum order qty 500Pegging Y Multiple order qtyLLC 1 Policy code 3

___________________________________

___________________________________

___________________________________

___________________________________

___________________________________

___________________________________

___________________________________

13

Item Master File (cont.)PHYSICAL INVENTORY USAGE/SALES

CODES

On hand 100 YTD usage/sales 1100Location W142 MTD usage/sales 75On order 100 YTD receipts 1200Allocated 75 MTD receipts 0Cycle 3 Last receipt 8/25Last count 9/5 Last issue 10/5Difference -2

Cost acct. 00754Routing 00326Engr 07142

___________________________________

___________________________________

___________________________________

___________________________________

___________________________________

___________________________________

___________________________________

14

The MRP Matrix

___________________________________

___________________________________

___________________________________

___________________________________

___________________________________

___________________________________

___________________________________

15

MRP: Example 1

Master Production Schedule

1 2 3 4 5

Clipboard 85 95 120 100 100Lapdesk 0 60 0 60 0

Item Master File

CLIPBOARD LAPDESK PRESSBOARDOn hand 25 20 150On order 175 (Period 1) 0 0(sch receipt)LLC 0 0 1Lot size L4L Mult 50 Min 100Lead time 1 1 1

___________________________________

___________________________________

___________________________________

___________________________________

___________________________________

___________________________________

___________________________________

16

MRP: Example 1 (cont.)Product Structure Diagrams

Clipboard

Lapdesk

Pressboard(2)

Trim(3’)

Beanbag(1)

Glue(4 oz)

Level 0

Level 0

Pressboard(1)

Clip Ass’y(1)

Rivets(2) Level 1

Level 1

___________________________________

___________________________________

___________________________________

___________________________________

___________________________________

___________________________________

___________________________________

17

ITEM: CLIPBOARD LLC: 0 PERIOD

LOT SIZE: L4L LT: 1 1 2 3 4 5

Gross Requirements 85 95 120 100 100Scheduled Receipts 175Projected on Hand 25Net RequirementsPlanned Order ReceiptsPlanned Order Releases

MRP: Example 1 (cont.)

___________________________________

___________________________________

___________________________________

___________________________________

___________________________________

___________________________________

___________________________________

18



LOT SIZE: L4L LT: 1 1 2 3 4 5

Gross Requirements 85 95 120 100 100Scheduled Receipts 175Projected on Hand 25 115Net Requirements 0Planned Order ReceiptsPlanned Order Releases

(25 + 175) = 200 units available(200 - 85) = 115 on hand at the end of Period 1

___________________________________

___________________________________

___________________________________

___________________________________

___________________________________

___________________________________

___________________________________

19


LOT SIZE: L4L LT: 1 1 2 3 4 5

Gross Requirements 85 95 120 100 100Scheduled Receipts 175Projected on Hand 25 115 20Net Requirements 0 0Planned Order ReceiptsPlanned Order Releases

115 units available(115 - 95) = 20 on hand at the end of Period 2


___________________________________

___________________________________

___________________________________

___________________________________

___________________________________

___________________________________

___________________________________

20


LOT SIZE: L4L LT: 1 1 2 3 4 5

Gross Requirements 85 95 120 100 100Scheduled Receipts 175Projected on Hand 25 115 20 0Net Requirements 0 0 100Planned Order Receipts 100Planned Order Releases 100

20 units available(20 - 120) = -100 — 100 additional Clipboards are requiredOrder must be placed in Period 2 to be received in Period 3


___________________________________

___________________________________

___________________________________

___________________________________

___________________________________

___________________________________

___________________________________

21


LOT SIZE: L4L LT: 1 1 2 3 4 5

Gross Requirements 85 95 120 100 100Scheduled Receipts 175Projected on Hand 25 115 20 0 0 0Net Requirements 0 0 100 100 100Planned Order Receipts 100 100 100Planned Order Releases 100 100 100

Following the same logic Gross Requirements in Periods 4 and 5 develop Net Requirements, Planned Order Receipts, and Planned Order Releases


___________________________________

___________________________________

___________________________________

___________________________________

___________________________________

___________________________________

___________________________________

22

ITEM: LAPDESK LLC: 0 PERIOD

LOT SIZE: MULT 50 LT: 1 1 2 3 4 5

Gross Requirements 0 60 0 60 0Scheduled ReceiptsProjected on Hand 20Net RequirementsPlanned Order ReceiptsPlanned Order Releases


___________________________________

___________________________________

___________________________________

___________________________________

___________________________________

___________________________________

___________________________________

23

ITEM: LAPDESK LLC: 0 PERIOD

LOT SIZE: MULT 50 LT: 1 1 2 3 4 5

Gross Requirements 0 60 0 60 0Scheduled ReceiptsProjected on Hand 20 20 10 10 0 0Net Requirements 0 40 50Planned Order Receipts 50 50Planned Order Releases 50 50

Following the same logic, the Lapdesk MRP matrix is completed as shown


___________________________________

___________________________________

___________________________________

___________________________________

___________________________________

___________________________________

___________________________________

24

ITEM: PRESSBOARD LLC: 1 PERIODLOT SIZE: MIN 100 LT: 1 1 2 3 4 5Gross RequirementsScheduled ReceiptsProjected on Hand 150Net RequirementsPlanned Order ReceiptsPlanned Order Releases

ITEM: CLIPBOARD LLC: 0 PERIODLOT SIZE: L4L LT: 1 1 2 3 4 5Planned Order Releases 100 100 100

ITEM: LAPDESK LLC: 0 PERIODLOT SIZE: MULT 50 LT: 1 1 2 3 4 5Planned Order Releases 50 50


___________________________________

___________________________________

___________________________________

___________________________________

___________________________________

___________________________________

___________________________________

25

ITEM: PRESSBOARD LLC: 1 PERIODLOT SIZE: MIN 100 LT: 1 1 2 3 4 5Gross Requirements 100 100 200 100 0Scheduled ReceiptsProjected on Hand 150Net RequirementsPlanned Order ReceiptsPlanned Order Releases



×2 ×2

×1 ×1×1


___________________________________

___________________________________

___________________________________

___________________________________

___________________________________

___________________________________

___________________________________

26

ITEM: PRESSBOARD LLC: 1 PERIODLOT SIZE: MIN 100 LT: 1 1 2 3 4 5Gross Requirements 100 100 200 100 0Scheduled ReceiptsProjected on Hand 150 50 50 0 0 0Net Requirements 50 150 100Planned Order Receipts 100 150 100Planned Order Releases 100 150 100




___________________________________

___________________________________

___________________________________

___________________________________

___________________________________

___________________________________

___________________________________

27

Planned Order Report

PERIOD

ITEM 1 2 3 4 5

Clipboard 100 100 100Lapdesk 50 50Pressboard 100 150 100


___________________________________

___________________________________

___________________________________

___________________________________

___________________________________

___________________________________

___________________________________

28

MRP Example 2:

Trumpet AssemblyItem On-Hand Lead Time (Wks)

T 50 1B 35 2C 15 4S 10 2V 20 3

Bell assembly (1) Valve Casing (1)

Valves (3)Slide assemblies (3)

Trumpet

Requirements include 82, 50, 95 units of T in weeks 8, 9, and 10plus the following component spares:

Spares 1 2 3 4 5 6 7 8 9 10B 12C 7S 10V 15

92 units of valves are scheduled to receive in week 3.

___________________________________

___________________________________

___________________________________

___________________________________

___________________________________

___________________________________

___________________________________

29

Lot Size: L4L Week 1 2 3 4 5 6 7 8 9 10T Gross Requirements 82 50 95

LT=1 Projected On-Hand=50 50 50 50 50 50 50 50Net Requirements 32 50 95Planned Order Receipt 32 50 95Planned Order Release 32 50 95

B Gross Requirements 32 50 107LT=2 Projected On-Hand=35 35 35 35 35 35 35 35 3

Net Requirements 47 107Planned Order Receipt 47 107Planned Order Release 47 107

C Gross Requirements 39 50 95LT=4 Projected On-Hand=15 15 15 15 15 15 15

Net Requirements 24 50 95Planned Order Receipt 24 50 95Planned Order Release 24 50 95

S Gross Requirements 72 150 285 10LT=2 Projected On-Hand=10 10 10

Net Requirements 72 150 285 10Planned Order Receipt 72 150 285 10Planned Order Release 72 150 285 10

V Gross Requirements 72 150 285 15LT=3 Scheduled Receipt 92

Projected On-Hand=20 20 20 40Net Requirements 110 285 15Planned Order Receipt 110 285 15Planned Order Release 110 285 15

___________________________________

___________________________________

___________________________________

___________________________________

___________________________________

___________________________________

___________________________________

30

Capacity Requirements Planning (CRP)

Computerized system that creates a load profile and identifies under-loads and over-loadsInputs

Planned order releases: from MRPRouting file: specifiies which machines or workers to use and in which order and lengthOpen orders file: the status of jobs that have already been released but not yet completed

___________________________________

___________________________________

___________________________________

___________________________________

___________________________________

___________________________________

___________________________________

Calculating Capacity

Rated CapacityTheoretical output that could be attained if a process were operating at full speed without interruption, exceptions, or downtime

Effective CapacityTakes into account the efficiency with which a particular product or customer can be processed and the utilization of the scheduled hours or work

Effective Daily Capacity = (no. of machines or workers) x (hours per shift) x (no. of shifts) x (utilization) x (efficiency)

31

___________________________________

___________________________________

___________________________________

___________________________________

___________________________________

___________________________________

___________________________________

Calculating Capacity (cont.)

UtilizationPercent of available time spent working

EfficiencyHow well a machine or worker performs compared to a standard output level

LoadStandard hours of work assigned to a facility

Load PercentRatio of load to capacity

32

___________________________________

___________________________________

___________________________________

___________________________________

___________________________________

___________________________________

___________________________________

33

CRPMRP planned

orderreleases

Routingfile

Capacityrequirements

planning

Openorders

file

Load profile foreach work center

___________________________________

___________________________________

___________________________________

___________________________________

___________________________________

___________________________________

___________________________________

Load Profile

graphical comparison of load versus capacityLeveling underload conditions:

Acquire more workPull work ahead that is scheduled for later time periodsReduce normal capacity

34

___________________________________

___________________________________

___________________________________

___________________________________

___________________________________

___________________________________

___________________________________

Reducing Over-load Conditions

1. Eliminating unnecessary requirements2. Rerouting jobs to alternative machines,

workers, or work centers3. Splitting lots between two or more machines4. Increasing normal capacity5. Subcontracting6. Increasing efficiency of the operation7. Pushing work back to later time periods8. Revising master schedule

35

___________________________________

___________________________________

___________________________________

___________________________________

___________________________________

___________________________________

___________________________________

36

Initial Load Profile

Hou

rs o

f cap

acity

1 2 3 4 5 6Time (weeks)

Normalcapacity

120 –110 –100 –90 –80 –70 –60 –50 –40 –30 –20 –10 –0 –

___________________________________

___________________________________

___________________________________

___________________________________

___________________________________

___________________________________

___________________________________

37

Adjusted Load ProfileH

ours

of c

apac

ity

1 2 3 4 5 6Time (weeks)

Normalcapacity

120 –110 –100 –90 –80 –70 –60 –50 –40 –30 –20 –10 –0 –

Pull ahead Push back

Push backOvertime

Work an

extra shift

___________________________________

___________________________________

___________________________________

___________________________________

___________________________________

___________________________________

___________________________________

mgs4700 operations management - georgia state universitydscgpz/mgs4700/chap15.pdf · resource...

Documents