1. Master Scheduling
Chapter 3

2. Master Production Schedule
3 months - 1 year - timeframe
What will manufacturing build?
How many? When?
What other components are needed?
What capacity constraints exist?
What material constraints exist?
It keeps priorities valid

3. Master Production Schedule
Deals with end items requirements
Drives the integrated Materials Requirements Plan
It is a priority plan for manufacturing
MPS has three functions:
to interlock the business plans and day-to-day operating plans
to provide a “control handle” for management on daily operations
to drive the formal, integrated planning and control system

4. Master Production Schedule
Information needed to create an MPS
Production Plan (Previously completed)
Forecasts for individual items
Actual orders received from customers & for stock replenishment
Inventory levels for individual items
Capacity constraints

5. Grand Scheme of Things Strategic Business Plan Production Plan
Master Plan
Production Plan
Planning
Master Production Schedule
Material Requirements Plan
Production Activity Control & Purchasing
Implementation

6. Developing an MPS Objectives Steps
Maintain desired level of customer service
Make best use of material, labor and equipment
Maintain inventory investment $$ at required levels
Steps
Develop a preliminary MPS
Check preliminary MPS against available capacity (rough-cut capacity planning)
Resolve any differences

7. Preliminary MPS
Page Do on Board.

8. Preliminary MPS Page 53. Walk Through Week 1: 50 + 100 - 75 = 75
(Projected Available + MPS - Forecast = Current Week Projected Available)
Week 1: = 75
Week 2: = 25
Week 3: = 95
Week 4: = 55
Week 5: = 85
Week 6: = 65
The MPS of 100 units was added at Week 1,3 & 5 to avoid a negative number
Week 1 2 3 4 5 6
Forecast 75 50 30 40 70 20
Projected available 25 95 55 85 65
MPS
100

9. Preliminary MPS MPS & Production Plan must match
Go back to Example on Page 51. Do on Board.

10. Rough-Cut Capacity Planning
Looks at whether critical resources (capacity) are available to support “preliminary” MPS
Look at Example on page 54
Look at Example on page 55.

11. Rough-Cut Capacity Planning
Resolution of Differences
Total Time VS Available Capacity
Three more items to look at
Resource use
Customer Service
$ (cost)

12. MPS Scheduled to finished-goods items
Make-to-Stock
Make-to-Order
Assemble to Order
MPS
Bottom of BOM
MPS
Top Assy of BOM
MPS
FAS
FAS
Few items; many components
Ships, Buses, Large Machine Tools
Many items; Many components; good commonality
Small Home Appliances, Electric Motors, Food products
Many items; many components; few modules; many options
Automobiles, computers, machine tools
MPS Scheduled to finished-goods items
MPS Scheduled to customer orders

13. Final Assembly Schedule (FAS)
Used in “Assemble to Order” & “Make to Order”
MPS
MPS
FAS
FAS

14. Planning Horizon Time span for the plan (how far into the future)
Shown: 26 weeks is the time span for this product B A C D E
Lead Time
= 6 weeks
= 2 weeks
= 5 weeks
= 8 weeks
= 16 weeks

15. Time Fences B A C D E
Lead Time
= 6 weeks
= 2 weeks
= 5 weeks
= 8 weeks
= 16 weeks
Lead times determine when a part will be available for delivery to the customer
Critical lead times determine the minimum planning period that must be used
As you get closer to the delivery date production becomes more inflexible
Changes to the MPS should only occur when
Customers cancel or change orders
Machine breakdowns, etc.
Supply problems
Higher scrap than anticipated

16. Zones and Time Fences Frozen zone Slushy zone Liquid zone
Actual Orders
(Emergency
Changes Only)
Frozen
Slushy
Liquid
Actual and Forecast
(Trade-offs)
Forecast Only
Due
Date
Demand
Time
Fence
Planning
2 weeks
26 weeks
Frozen zone
Capacity and materials are committed to specific orders
Requires senior management approval to change
Slushy zone
Commitment is to a lesser extent
Changes are easier to make
Liquid zone
Changes can easily be made

17. MPS & Sales
MPS is not a sales forecast, it is instead, a forecast of production.
It may not necessarily be what we want; it should be what we can do.
MPS must be realistic & achievable; otherwise, the plan fails, deliveries are not met, & manufacturing has to react to circumstances rather than planning for them (Proactive VS Reactive)

18. MPS and Delivery Promises
As orders are received, they “consume” available production and inventory
Any part not consumed is Available-To-Promise
"Available To Promise" (ATP) simply means that a product is in stock and can be promised to a buyer.
With Available To Promise (ATP) it is possible to see how much inventory or projected inventory is not committed to current customer orders and is therefore available for order promising.
Customer
Orders
Available-To-
Promise
Time
Units
Production Capacity or Inventory

19. Available-To-Promise
Customer Order
Can it be filled from existing inventory without changing schedule?
Looks ahead for availability of product

20. Available-To-Promise
Go over Figure 3.8 page 60
Also Figure 3.8 (bottom of page 61)

21. Available-To-Promise

22. Projected Available Balance
Forecast is not always accurate
PAB takes both Forecast & Customer Order into account
Two methods
Prior Demand Time Fence
PAB = prior period PAB or on-hand balance + MPS - customer orders
After Demand Time Fence
PAB = prior period PAB + MPS – [greater of customer orders or forecast]

23. Projected Available Balance
The demand time fence is the end of week 3, the order quantity is 100, 40 are available at the beginning of the period.
Before Demand Time Fence
(prior period PAB or on-hand balance + MPS - customer orders)
Week 1: = 1
Week 2: = 59
Week 3: = 20
After Demand Time Fence
(prior period PAB + MPS – [greater of customer orders or forecast])
Weed 4: = 80
Week 5: = 40
Week 1 2 3 4 5
Forecast 40
Customer orders 39 42 33 32
Week 1 2 3 4 5
Projected Available Balance 40 1 59 20 80 40
MPS
100
100

24. Summary MPS Major Functions
Forms the link between APP & what manufacturing builds
Plans capacity requirements - the MPS determines the capacity required
Plans material requirements - the MPS drives the (MRP)
Keeps priorities valid - the MPS is a priority plan for manufacturing

25. Summary MPS Links Sales & Production
Aids in making order promises - the MPS is a plan for what is to be produced & when
Informs sales & manufacturing when goods will be available for delivery
Creates a contract between marketing & manufacturing - an agreed-upon plan

26. Summary
The MPS must be realistic & based on what production can & will do, if not,
Resource overloads or underloads do occur
Unreliable schedules result & delivery performance suffers
High levels of work-in-process (WIP) inventory build-up
Customer service is poor
Planning system loses credibility