MRP numerical ppc module 4 numericals rubish

Ppc model numericals mrp

1. Material Requirement Planning (MRP)
1
MRPintegratesdatafromproductionschedules
(MPS)withinventoryrecords,scheduled
receiptsandthebillofmaterials(BOM)to
determinepurchasingandproductionschedules
forthecomponentsrequiredtobuildaproduct.

2. Material Requirement Planning (MRP)
2
MRPisacomputer-basedinventory
managementsystemdesignedtoassist
productionmanagersinschedulingand
placingordersforitemsofdependentdemand.
Computer-basedinformationsystemthat
translatesmasterschedulerequirementsfor
enditemsintotime-phasedrequirementsfor
subassemblies,componentsandrawmaterials.

3. Independent and Dependent Demand
3
Independent Demand
A
B(4) C(2)
D(2) E(1)D(3) F(2)
Dependent Demand
Independent demand is uncertain.
Dependent demand is certain.

4. Dependent Demand
4
Dependentdemand:Demandforitems
thataresubassembliesorcomponent
partstobeusedinproductionoffinished
goods.
Oncetheindependentdemandisknown,
thedependentdemandcanbedetermined.

5. Material Requirement Planning (MRP)
5
The MRP is designed to answer
three questions:
Whatis needed?
Howmuch is needed?
Whenis it needed?

6. Material Requirement Planning (MRP)
6

7. MRP Inputs
7
MasterProductionSchedule(MPS)
Bill-of-Material(BOM)
On-handinventorydata
Expectedreceipts(outstanding
purchaseorders)
LeadTimeinformation

8. MRP Inputs
8
MasterProductionSchedule(MPS)–Stateswhichenditemsaretobe
produced,whentheyareneeded,andinwhatquantities
BillofMaterials(BOM)–alistingofalloftherawmaterials,parts,and
sub-assembliesneededtoproduceoneunitofaproduct
InventoryRecords–includesinformationonthestatusofanitemduring
theplanninghorizon,eg.quantity,supplier,orderleadtime,lotsize
Cumulativeleadtime-Thesumoftheleadtimesthatsequentialphases
ofaprocessrequire,fromorderingofpartsorrawmaterialsto
completionoffinalassembly
Productstructuretree-Visualdepictionoftherequirementsinabillof
materials,whereallcomponentsarelistedbylevels

9. Assembly Diagram
9

10. Product Structure Tree
10
Chair
Seat
Legs (2)
Cross
bar
Side
Rails (2)
Cross
bar
Back
Supports (3)
Leg
Assembly
Back
Assembly
Level
0
1
2
3

11. Planning Horizon
11
1 2 3 4 5 6 7 8 9 10
Procurement
Fabrication
Subassembly
Assembly

12. Assembly Time Chart
12
1 2 3 4 5 6 7 8 9 1011
Procurement of
raw material D
Procurement of
raw material F
Procurement of
part C
Procurement of
part H
Procurement of
raw material I
Fabrication
of part G
Fabrication
of part E
Subassembly A
Subassembly B
Final assembly
and inspection

13. Time-Phased Product Structure
13
| | | | | | | |
1 2 3 4 5 6 7 8
Time in weeks
F
2 weeks
3 weeks
1 week
A
2 weeks
1 week
D
E
2 weeks
D
G
1 week
Start production of D
Must have D and E
completed here so
production can
begin on B
1 week
2 weeks to
produce
B
C
E

14. MRP Processing
Week Number 1 2 3 . . n
Gross Requirements
Scheduled Receipts
Projected on hand
Net requirements
Planned-order-receipt
Planned-order release
14

15. MRP Processing
Gross requirements
•Total expected demand
Scheduled receipts
•Open orders scheduled to arrive
Projected On Hand
•Expected inventory on hand at the beginning of each
time period
Net requirements
•Actual amount needed in each time period
Planned-order receipts
•Quantity expected to be received at the beginning of the
period & offset by lead time
Planned-order releases
•Planned amount to order in each time period
15

16. MRP Primary Reports
Plannedorders-scheduleindicatingthe
amountandtimingoffutureorders
Orderreleases-Authorizationforthe
executionofplannedorders
Changes-revisionsofduedatesororder
quantities,orcancellationsoforders

17. MRP Secondary Reports
Performance-controlreports–Evaluation
ofsystemoperation,includingdeviations
fromplansandcostinformation
Planningreports–Datausefulfor
assessingfuturematerialrequirements
ExceptionReports–Dataonmajor
discrepanciesencountered

18. Other Considerations
Safety Stock
Lot sizing technique
Lot-for-lot ordering
Economic/Fixed order quantity
Fixed-period ordering

19. Updating the MRP System
An MRP is not a static document
As time passes
Some orders get completed
Other orders are nearing completion
New orders will have been entered
Existing orders will have been altered
Quantity changes
Delays
Missed deliveries

20. Updating the MRP System
Regenerativesystem:MRPrecordsareupdated
periodically
Essentiallyabatchsystemthatcompilesallchanges
thatoccurwithinthetimeintervalandperiodically
updatesthesystem
Net-changesystem:MRPrecordsareupdated
continuously
Theproductionplanismodifiedtoreflectchangesas
theyoccur

21. MRP in Services
Food catering service
End item => catered food
Dependent demand => ingredients for
each recipe, i.e. bill of materials
Hotel renovation
Activities and materials “exploded” into
component parts for cost estimation and
scheduling

22. Benefits of MRP
Lowlevelsofin-processinventories
Abilitytotrackmaterialrequirements
Abilitytoevaluatecapacityrequirements
Meansofallocatingproductiontime
Abilitytoeasilydetermineinventoryusagebyback-
flushing
Backflushing:Explodinganenditem’sbillofmaterialsto
determinethequantitiesofthecomponentsthatwereused
tomaketheitem.

23. MRP Evolution
MRP
Closed Loop
MRP
MRP II
ERP
Schedule Materials
Schedule Materials
Incorporate Feedback
Schedule & Purchase Materials
Coordinate w/ Mfg Resources

24. Q1) Spring (example)
Compute the MRP for a certain product
(spring)
Following data is given
Order quantity is 50 units (Fixed order Qty)
Lead Time (LT) is one week
24

25. Q1) MRP Table (Given) 1 2 3 4 5
Gross Requirements 10 40 10
Scheduled receipts (begin) 50
Projected Available
Balance (ending) 4

Net Requirements
Planned Order Receipts
Planned Order Releases


25

26. Q1) MRP Table (solution) 1 2 3 4 5
Gross Requirements 10 40 10
Scheduled receipts (begin) 50
Projected Available
Balance (ending) 4

54

44

Net Requirements
Planned Order Receipts
Planned Order Releases


26

27. Q1) MRP Table (solution) 1 2 3 4 5
Gross Requirements 10 40 10
Scheduled receipts (begin) 50
Projected Available
Balance (ending) 4

54

44

44

4

Net Requirements
Planned Order Receipts
Planned Order Releases


27

28. Q1) MRP Table (solution) 1 2 3 4 5
Gross Requirements 10 40 10
Scheduled receipts (begin) 50
Projected Available
Balance (ending) 4

54

44

44

4


Net Requirements 6
Planned Order Receipts
Planned Order Releases


6 units short
28

29. Q1) MRP Table (solution) 1 2 3 4 5
Gross Requirements 10 40 10
Scheduled receipts (begin) 50
Projected Available
Balance (ending) 4

54

44

44

4


Net Requirements 6
Planned Order Receipts 50
Planned Order Releases 50


Order 50 units week earlier 29Fixed order qty(50)

30. Q1) MRP Table (solution) 1 2 3 4 5
Gross Requirements 10 40 10
Scheduled receipts (begin) 50
Projected Available
Balance (ending) 4

54

44

44

4

4 + 50 -10 =
44
Net Requirements 6
Planned Order Receipts 50
Planned Order Releases 50


Ending inventory
30

31. Q2) Spring (example)
Compute the MRP for a certain product
(spring)
Following data is given
Order quantity is 50 units (Fixed order Qty)
Safety Stock of 20 units to be kept
Lead Time (LT) is one week
31

32. Q2) MRP Table (Given) 1 2 3 4 5
Gross Requirements 10 40 10
Scheduled receipts (begin) 40
Projected Available
Balance (ending) 4

Net Requirements
Planned Order Receipts
Planned Order Releases


32

33. Q2) MRP Table (solution) 1 2 3 4 5
Gross Requirements 10 40 10
Scheduled receipts (begin) 40
Projected Available
Balance (ending) 4

44

34

34

Net Requirements
Planned Order Receipts
Planned Order Releases


33

34. Q2) MRP Table (solution) 1 2 3 4 5
Gross Requirements 10 40 10
Scheduled receipts (begin) 40
Projected Available
Balance (ending) 4

44

34

34
34 + 50 – 40
= 44


Net Requirements 6 + 20 = 26
Planned Order Receipts 50
Planned Order Releases 50


6 units short to fulfill gross requirement &
20 units short to fulfill safety stock requirement
34

35. Q2) MRP Table (solution) 1 2 3 4 5
Gross Requirements 10 40 10
Scheduled receipts (begin) 40
Projected Available
Balance (ending) 4

44

34

34
34 + 50 – 40
= 44

34
Net Requirements 6 + 20 = 26
Planned Order Receipts 50
Planned Order Releases 50


35

36. Q3) Spring (example)
Compute the MRP for a certain product
(spring)
Following data is given
Lot for Lot
Safety Stock of 20 units to be kept
Lead Time (LT) is one week
36

37. Q3) MRP Table (Given) 1 2 3 4 5
Gross Requirements 10 40 10
Scheduled receipts (begin) 30
Projected Available
Balance (ending) 4

Net Requirements
Planned Order Receipts
Planned Order Releases


37

38. Q3) MRP Table (solution) 1 2 3 4 5
Gross Requirements 10 40 10
Scheduled receipts (begin) 30
Projected Available
Balance (ending) 4

34

24

Net Requirements
Planned Order Receipts
Planned Order Releases


38

39. Q3) MRP Table (solution) 1 2 3 4 5
Gross Requirements 10 40 10
Scheduled receipts (begin) 30
Projected Available
Balance (ending) 4
34 24 24
24 + 36 – 40
= 20


Net Requirements 16 + 20 = 36
Planned Order Receipts 36
Planned Order Releases 36


16 units short to fulfill gross requirement &
20 units short to fulfill safety stock requirement
39

40. Q3) MRP Table (solution) 1 2 3 4 5
Gross Requirements 10 40 10
Scheduled receipts (begin) 30
Projected Available
Balance (ending) 4
34 24 24 20

20 + 10 - 10
= 20
Net Requirements 36 10
Planned Order Receipts 36 10
Planned Order Releases 36 10


10 units short to fulfill safety stock requirement
40

41. Q4) 1605 Snow Shovel
1605
Snow Shovel
048
Scoop-shaft
connector
13122
Top Handle
Assy314 scoop assembly
118 Shaft (wood)
062 Nail (4)
14127
Rivet (4)
41

42. Q4) 314 scoop assembly
314 scoop assembly
14127 Rivet (6)
019 Blade (steel)
2142 Scoop (aluminum)
42

43. Q4) 13122 Top Handle Assembly
1118
Top handle
Coupling (steel)
11495 Welded
Top handle bracket
Assembly
13122 Top Handle Assembly
457 Top handle
(wood)
129 Top Handle
Bracket (steel)
082 Nail (2)
43

44. Q4) BOM Explosion
Process of translating net requirements
into components part requirements
Take into account existing inventories
Consider also scheduled receipts
44

45. Q4) BOM Explosion Example
Need to make 100 shovels
We are responsible for handle
assemblies.
45

46. Q4) 13122 Top Handle Assembly
1118
Top handle
Coupling (steel)
11495 Welded
Top handle bracket
Assembly
13122 Top Handle Assembly
457 Top handle
(wood)
129 Top Handle
Bracket (steel)
082 Nail (2)
46

47. Q4) Net Requirements
SchGrossNet
Part DescriptionInvRecReq Req
Top handle assy 25--100 75
Top handle 2225
Nail (2 required)4 50
Bracket Assy 27--
Top bracket 15--
Top coupling 3915
47

48. Q4) Net Requirements
SchGrossNet
Part DescriptionInvRecReq Req
Top handle assy 25--100 75
Top handle 222575 28
Nail (2 required)4 50150 96
Bracket Assy 27--75 48
Top bracket 15--
Top coupling 3915
48

49. Q4) Net Requirements
SchGrossNet
Part DescriptionInvRecReq Req
Top handle assy 25--100 75
Top handle 222575 28
Nail (2 required)4 50150 96
Bracket Assy 27--75 48
Top bracket 15--48 33
Top coupling391548 --
49

50. Q4) Timing of Production
This tells us how many of each part we
need
Doesn’t tell when to start
Start as soon as possible?
50

51. Q4) 13122 Top Handle Assy
13122 Top handle
LT = 2

1

2

3

4

5

6

7

8

9

10
Gross Req 20 10 20 5 35 10
Sch receipts
Proj. Avail Bal
(ending)

25

Net Req
Planned Order Receipt
Planned Order Release


Order policy: Lot-for-lot
51

52. Q4) 13122 Top Handle Assy-2
13122 Top handle
LT = 2

1

2

3

4

5

6

7

8

9

10
Gross Req 20 10 20 5 35 10
Sch receipts
Proj. Avail Bal
(ending)

25

25

5

5

0

0

0

0

0

0

0
Net Req 5 20 5 35 10
Pl Order Rec 5 20 5 35 10
Pl Order Rel 5 20 5 35 10


Order policy: Lot-for-lot
52

53. Q4) 457 Top Handle
13122 Top handle
LT = 2

1

2

3

4

5

6

7

8

9

10
Gross Req 20 10 20 5 35 10
Sch receipts
Proj. Avail Bal
(ending)

25

25

5

5

0

0

0

0

0

0

0
Net Req 5 20 5 35 10
Pl Order Rec 5 20 5 35 10
Pl Order Rel 5 20 5 35 10



LT = 2

1

2

3

4

5

6

7

8

9

10
Gross Req 5 20 5 35 10
Sch receipts 25
Proj. Avail Bal
(ending)

22

22





Net Req
Pl Order Rec
Pl Order Rel


One Top handle
required for
Each assembly
53

54. Q4) 457 Top Handle

LT = 2

1

2

3

4

5

6

7

8

9

10
Gross Req 5 20 5 35 10
Sch receipts 25
Proj. Avail Bal
(ending)

22

22

17



Net Req
Pl Order Rec
Pl Order Rel


Order policy: Lot-for-lot
54

55. Q4) 457 Top Handle

LT = 2

1

2

3

4

5

6

7

8

9

10
Gross Req 5 20 5 35 10
Sch receipts 25
Proj. Avail Bal
(ending)

22

22

17

42

22

17

17

0

0

0

0
Net Req 18 10
Pl Order Rec 18 10
Pl Order Rel 18 10


Order policy: Lot-for-lot
55

56. Q4) 082 Nail (2 required)
LT = 1
Lot Size = 50

1

2

3

4

5

6

7

8

9

10
Gross Req 10 40 10 70 20
Sch receipts 50
Proj. Avail Bal
(ending)

4

54



Net Req
Pl Order Rec
Pl Order Rel


13122 Top handle
LT = 2

1

2

3

4

5

6

7

8

9

10
Gross Req 20 10 20 5 35 10
Sch receipts
Proj. Avail Bal
(ending)

25

25

5

5

0

0

0

0

0

0

0
Net Req 5 20 5 35 10
Pl Order Rec 5 20 5 35 10
Pl Order Rel 5 20 5 35 10


Twonails for
Each assembly
56

57. Q4) 082 Nail (2 required)
LT = 1
Lot Size = 50

1

2

3

4

5

6

7

8

9

10
Gross Req 10 40 10 70 20
Sch receipts 50
Proj. Avail Bal
(ending)

4

54

44

44

4

44

44

24

4

4

4
Net Req 6 26
Pl Order Rec 50 50
Pl Order Rel 50 50


57

58. Q4) 11495 Bracket Assembly
13122 Top handle
LT = 2

1

2

3

4

5

6

7

8

9

10
Gross Req 20 10 20 5 35 10
Sch receipts
Proj. Avail Bal
(ending)

25

25

5

5

0

0

0

0

0

0

0
Net Req 5 20 5 35 10
Pl Order Rec 5 20 5 35 10
Pl Order Rel 5 20 5 35 10



LT = 2

1

2

3

4

5

6

7

8

9

10
Gross Req 5 20 5 35 10
Sch receipts
Proj. Avail Bal
(ending)

27







Net Req
Pl Order Rec
Pl Order Rel


One bracket for
Each assembly
58

59. Q4) 11495 Bracket Assembly

LT = 2

1

2

3

4

5

6

7

8

9

10
Gross Req 5 20 5 35 10
Sch receipts
Proj. Avail Bal
(ending)

27

27

22

22

2

0

0

0

0

0

0
Net Req 3 35 10
Pl Order Rec 3 35 10
Pl Order Rel 3 35 10


Order policy: Lot-for-lot
59

60. Q4) 129 Top Bracket

LT = 1

1

2

3

4

5

6

7

8

9

10
Gross Req 3 35 10
Sch receipts
Proj. Avail Bal
(ending)

15



Net Req
Pl Order Rec
Pl Order Rel



LT = 2

1

2

3

4

5

6

7

8

9

10
Gross Req 5 20 5 35 10
Sch receipts
Proj. Avail Bal
(ending)

27

22

22

2





Net Req 3 35 10
Pl Order Rec 3 35 10
Pl Order Rel 3 35 10


60
Onetop bracket for
Each assembly

61. Q4) 129 Top bracket

LT = 1

1

2

3

4

5

6

7

8

9

10
Gross Req 3 35 10
Sch receipts
Proj. Avail Bal
(ending)

15

15

15

12

12

0

0

0

0

0

0
Net Req 23 10
Pl Order Rec 23 10
Pl Order Rel 23 10


Order policy: Lot-for-lot
61

62. Q4) 1118 Top handle coupling
LT = 3
Safety Stock = 20

1

2

3

4

5

6

7

8

9

10
Gross Req 3 35 10
Sch receipts
Proj. Avail Bal
(ending)

39



Net Req
Pl Order Rec
Pl Order Rel



LT = 2

1

2

3

4

5

6

7

8

9

10
Gross Req 5 20 5 35 10
Sch receipts
Proj. Avail Bal
(ending)

27

22

22

2





Net Req 3 35 10
Pl Order Rec 3 35 10
Pl Order Rel 3 35 10


62
Onetop coupling
for Each assembly
15

63. Q4) 1118 Top handle coupling
LT = 3
Safety Stock = 20

1

2

3

4

5

6

7

8

9

10
Gross Req 3 35 10
Sch receipts 15
Proj. Avail Bal
(ending)

39

39

54

51

51

20

20

20

20

20

20
Net Req 4 10
Pl Order Rec 4 10
Pl Order Rel 4 10


63
Order policy: Lot-for-lot