Supporting Slides

Systems for Planning & Control in Manufacturing

Produced by D K Harrison and D J Petty 21/04/02 Sld - 0000

XSupporting Slides

Professor David K HarrisonGlasgow Caledonian University

Dr David J PettyThe University of Manchester Institute of Science and Technology

Systems for Planning & Control in Manufacturing:Systems and Management for Competitive Manufacture

ISBN 0 7506 49771


Produced by D K Harrison and D J Petty 21/04/02 Sld -

MPS - Overview

Definition

The anticipated build schedule for those items assigned to the Master Scheduler. The master scheduler maintains this schedule and in turn it becomes a set of planning numbers which drives MRP. It represents what the company plans to produce expressed in specific configurations, quantities and dates. The MPS is not a sales forecast which represents a statement of demand. The MPS must take account of the forecast, the Production Plan (SOP), and other important considerations such as order backlog, availability of material, availability of capacity, management policy and goals etc.

MPS - BalancingSupply and Demand

Material Requirements Planning

Master Production Scheduling

Sales and Operations Planning

BusinessPlanning

Capacity Requirements Planning

Realistic

Shop Floor Control

No

Yes

Purchasing

18

1801



MPS - Examples

C D

A

E F

B

A

B

SalesRequirement

ResourceItem

Assembly 1000

Assembly 1000

C

D

NetRequirement

ResourceItem

MachineShop 1000

1000

E

F

1000

1000

ActualProduction

MachineShop

MachineShop

MachineShop

Total 4000

Assembly Shop Capacity = 2000Machine Shop Capacity = 3000

ActualProduction

Total 2000

Sales Demand400,000 MRP

"x" req. = 400,000

"y" req. = 400,000

ActualProduction

ActualPurchase

=

=

x

y

18

400,000

300,000

1000

500

1000

500

3000

500

500

1000

1802



Reasons to Master Schedule - 1

Lumpy

Jan Mar May Jul Sep Nov0

20

40

60

80

100

120

Sa

les

Months

18

LoadCapacity

1803



Month-End Biased

Wk1 Wk3 Wk5 Wk7 Wk10 Wk120

20

40

60

80

100

120

Sa

les

Weeks

Reasons to Master Schedule - 2

LoadCapacity

18

1804



Reasons to Master Schedule - 3 18

Seasonal

Jan Mar May Jul Sep Nov0

20

40

60

80

100

120

Sa

les

Months

LoadCapacity

1805



• A Company May Also Sequence Work to Minimise Changeovers

• The MPS Must be Kept Relatively Stable to Minimise Planner Action Messages

Overload

Wk1 Wk3 Wk5 Wk7 Wk10 Wk120

20

40

60

80

100

120

Sa

les

Weeks

Reasons to Master Schedule - 4 18

LoadCapacity

1806



MPS Overview 18

CapacityProductData

Demand

MasterSchedule

MasterProductionScheduling

DP1031DP1032DP1033DP1034

DP1029DP1030

1,0001,5002,000

2001,000

121,0001,5002,000

1,0007,000

151,0001,5002,000

2002,000

161,0001,5002,000

2,000

171,0001,5002,000

2002,000

181,0001,5002,000

2,000

191,0001,5002,000

2002,000

201,0001,5002,000

2001,000

141,0001,5002,000

1,000

13111,0001,5002,000

1,000

Part No.

Planning Horizon

MPS

• Statement of Supply

• Demand - Actual or Forecast

• Defined in Terms of End-Items or Planning BOM

• Drives MRP

• Crucial Element in Management Control

Weeks

1807



Planning Horizon 18

MPS Planning Horizon

Significance of ChangeHigh Low

DemandTimeFence(DTF)

Manufacturing Committedto Plan

Changes Subjectto Approval

Capacity Trade-offsPermitted

Overall Levels ofProduction Defined

Capacity Definedby SOP

PlanningTimeFence(PTF)

Now

• Prevents Orders Being Scheduled

• Takes Actual Demand Only

• Takes Greater of Planned and Actual Demand

Cumulative Manufacturing Lead Time Cumulative Purchasing Lead Time

1808



Emergency Demand 18

Short Order Shop

Uncommitted Capacity

Trade Offs

Uncommitted Inventory

100%

1809



MPS Mechanics – 1

Load

Capacity

Time

Lo

ad

/Ca

pa

cit

y

NormalLead Time

Planned

AutomaticReschedule

Explode toNext Level

OrderType

Created Automatically by MRP

Created Manually by Planner

Planned or Firm Planned Orders are Converted into Scheduled Receipts

Firm Planned

Scheduled Receipt

Comment

Yes Yes

No Yes

No No

18

1810



MPS Mechanics - 2 18

• MPS Orders Are Created Manually

• Action Messages Assist Planner

• MPS Orders are Firm Planned

• Available to Promise (ATP) Used for Order Promising

• Time Fences Can be Ignored (Time Fence Violation)

• RCCP is also a Valuable Tool in Master Scheduling

1811



MPS Example 18

Independent Forecast

Actual Demand

1 2 3 4 5 6 7 8

20 20 20 20 20 20

5

SOH

Time

Part No: K7

Lead Time: 3

Order Qty: 60

Available to Promise

Projected Available Balance 10 5 45 25 65 45 25 525

15 10 20

MPS (Receipt) 60 60

Demand Time Fence Planning Time Fence

5 30 60

1812



Two Level MPS - 1

Make to StockMake to OrderEngineer to Order

Configure to Order

End Items(Single Level MPS)

Planner Items(Two Level MPS)

Variety

Finished Goods

Components

Raw Materials

"D"

“P"

18

1813



Two Level MPS – 2

Components

End-Items - Actual Product

O S

NPT I O

Level 2 - MPS Driven by Generic Forecast Demand

Level 1 – Final Assembly Schedule (FAS) Driven by Specific Customer Demand

Inventory Held at Pointof Minimum Inventory

Planner Items - Fictitious

18

1814



Two Level MPS - 3

Car

Engine Body Gearbox Trim

1.4

1.6

1.8

XR12

1.8D

Saloon

Estate

Cabriolet

Manual

Auto

PIV

Electric

B

L

LX

GL

Ghia

Sport

Red

Blue

Black

Green

White

Maroon

Colour Options

CD

Electric Sun Roof

Mobile Phone

Passenger Air Bag

Metallic Paint

ABS

Permutations = x x x x x =6 3 3 6 6 6 11664

OptionsTrimGearboxBodyEngine Colour

1.4 (25%)

1.6 (25%)

1.8 (20%)

XR12 (10%)

1.8D (15%)

Electric (5%)

Saloon (65%)

Estate (30%)

Cabriolet (5%)

Manual (85%)

Auto (10%)

PIV*(5%)

B (20%)

L (20%)

LX (20%)

GL (18%)

Ghia (10%)

Sport (12%)

Red (20%)

Blue (30%)

Black (20%)

Green (5%)

White (5%)

Maroon (20%)

CD (10%)

Electric Sun Roof (10%)

Mobile Phone (5%)

Passenger Air Bag (5%)

Metallic Paint (25%)

ABS (35%)

18

*PIV = Positively Infinitely Variable1815



Management Aspects of MPS - 1 18

Purchasing

COSTS!

Sales

SELL!

BUY!

Production

MAKE!

Finance

Logistics

?

Engineering

DESIGN!

1816



Management Aspects of MPS - 2 18

• Adoption of Plan

• MPS Meetings

• Senior Management Driven

• Master Production Scheduler

1817



Master Scheduler - Responsibilities 18

• Maintain the MPS

• Provide Management with Information

• Ensure the MPS Reflects the Aggregate Plan

• Ensures the MPS is Feasible

1818



The Ideal Master Scheduler 18

Experience• 10 Years in Manufacture• 10 Years in Sales/Marketing• 5 Years in Production/Material Control• 2-3 Years in Finance Desirable

Qualifications• Business Administration• Mechanical, Electrical and Production Engineering• Production and Inventory Management

Age• An Energetic 35 Year Old

1819



The Practical Master Scheduler

• Company Employee

• Good Communicator and Diplomat

• Good All-Round Product/Business Knowledge

• Respected in the Organisation

• The Person the Company Wants to Develop

18

1820



Planning and ExecutionManufacturingManufacturing OverloadLong Work-to-ListsPast Due OrdersShortagesHigh WIPLong Lead Times

Sales and PlanningLong Planner Action ListsUnreliable Delivery Promises

GeneralHigh Inventory

Result:

Execution

Input (MPS)

WIP

Output

18

1821



MPS - Summary

• Supply - Demand Balance

• Mechanism for Control of the Organisation

• Tool for Defining Priorities

• Mechanism for Ensuring Feasible and Stable Schedules

• Requires Management Commitment

• Fundamental to All Manufacturing Management Techniques

• MPS Formalises a Process that Must be Undertaken

18

1822



Course Book

Systems for Planning & Control in Manufacturing:

Systems and Management for Competitive Manufacture

Professor David K HarrisonDr David J Petty

ISBN 0 7506 49771

X

0000

Documents

Supporting Slides