1. Facilities Planning and Design Course code: 1704031511
Spring
Required Text: Tompkins et al., (2003). Facilities Planning, 3rd or later Edition, John Wiley and Sons Inc.
Students are encouraged to refer to the text book, and to take notes during the lectures.

2. Facilities Planning and Design Course code: 1704031511
Spring
Required Text: Tompkins et al., (2003). Facilities Planning, 3rd or later Edition, John Wiley and Sons Inc.
Students are encouraged to refer to the text book, and to take notes during the lectures.

3. Chapter 2: Product, Process and Schedule Design
Chapter Topics:
PART I
Facilities Planning Process for Manufacturing and Assembly Facilities.
Relationship between PP&S design and Facilities Planning.
Product Design
PART II
Process Design
Process identification
Process selection
Process sequencing
PART III
Schedule Design
Quantity of the product
Equipment requirements
Operator requirements
PART IV
Facilities Design

4. Facilities Planning Process for Manufacturing and Assembly Facilities.
1. Define the products to be manufactured and /or assembled.
2. Specify the required manufacturing process and/or assembly processes and related activities.
3. determine the interrelationships among the activities.
4. Determine the space requirements for all the activities.
5.Generate alternative facilities plans.
6. Evaluate the alternative facilities plans.
7. Select the preferred facilities plan.
8. Implement the facilities plan.
9. Maintain and adapt the facilities plan.
10. Update the products to be manufactured and/or to be assembled and redefine the objective of the facility.

5. Relationship between PP&S design and Facilities Planning.
Before we start developing alternative facility plans, we should have answers for the following questions:
What is to be produced?
How are the products to be produced?
When are the products to be produced?
How much of each product will be produced?
For how long will the product be produced?
Where will the products be produced?

6. Schedule design Schedule design provides answers to questions
involving:
Production quantity - lot size decisions
When to produce - production scheduling
How long to produce – marketing forecasts
Schedule design decisions impact machine selection, number of machines, number of shifts, number of employees, space requirements, storage equipment, material handling equipment, personnel requirements, storage policies, unit load design, building size, etc.
We design facilities for major parts and operations
What do we need to know to start designing our facilities
Number of products demanded by the market
Number of products to be produced
Number of machines required
Number of employees required
Sequence of operations
Relationships between departments

7. Schedule design - Marketing information
Objective – market estimate
Data from marketing:
Production volumes
Trends
Future demands
Min information provided by marketing is shown in Table 2.2
Detailed information by marketing is shown in Table 2.3:

9. Volume-variety chart – Pareto law
More general items produced everyday: Mass production area (High volume)
Items that are produced maybe by special orders: Job shop area (Low volume)
85% of the production volume is attributed to 15% of the product mix
Therefore when facilities are designed, top 15% of the items that are produced should be considered the most.
If no products dominate the production flow, a general job shop facility is suggested

10. Schedule design – Process requirements
Specification of process requirements has three phases:
Determination of the quantity to be manufactured for each component
Identification of each equipment required by each operation
Overall equipment requirements
Scrap Estimates (Examples solved during the class)
Determination of the quantity to be manufactured for each component
For high volume production
The estimation of scrap

11. Schedule design – Process requirements
Specification of process requirements has three phases:
Determination of the quantity to be manufactured for each component
Identification of each equipment required by each operation
Overall equipment requirements
Reject Allowance Problem
Determination the number of additional units to allow when the number of items to produce are very few and rejects randomly occur
For low volume production
The cost of scrap is very high

12. Reject allowance problem
X: Number of good units, random variable
p(x): Probability of producing exactly x good units
Q: Quantity of production
C(Q, x): Cost of producing Q units, with x good units
R(Q, x): Revenue from producing Q units, with x good units
P(Q, x): Profit from producing Q units, with x good units P(Q, x) = R(Q, x) - C(Q, x)
E[P(Q)]: Expected profit when Q units are produced
X and Q are discrete variables, therefore p(X) is a discrete probability function
Objective: Determine production quantity Q that has exactly x good units and
maximize the expected profit: E[P(Q)]
Other useful information is what is the probability of loosing money if Q is produced.

13. Reject allowance problem Example
A foundry produces castings to order. An order for 20 custom-designed castings has been received. The casting process costs $1,100 per unit scheduled. If a casting is not sold, it has a recycle value of $200. The customer has indicated a willingness to pay $2,500 per casting for 20 acceptable castings – no more, no less!
• Based on historical records, the probability distributions given in Table 2.6 have been estimated.
• How many castings should be scheduled for production to maximize the expected profit?
• What is the probability of losing money at this production level?
Example Summary
20 castings are needed (no more, no less)
 C = $1100/unit
 Price = $2500
Recycling Value = $200
Determine Q that max. E (Profit)

14. Table 2.6 Probability Distribution for Number of Good Castings (x) out of Q

15. Revenue, cost and profit functions for the reject allowance problem

16. Profit for producing Q and having different x good units among them
Expected Profit for producing Q and having different x good units among them

18. Equipment fractions
The quantity of equipment required for an operation
Most of the time facilities need fraction of machines
How can we determine the number of machines we need in order to produce Q items?
F: the required number of machines per shift
S: the standard time per unit produced [min]
Q: the number of units to be produced per shift
E: actual performance (as % of standard time)
H: amount of time available per machine [min]
R: reliability of machine (as % “uptime”)

19. Machine assignment problem
Operator Requirements
Machine assignment problem

20. Machine assignment problem
If we know the activities needed and the time required to complete each activity, we can determine the ideal number of machines per operator n’ (for identical machines)
If found n’ is not an integer value (it will not be in most cases), how do we determine the number of machine for each person (m)?
If m < n’ then operator will be idle
If m > n’ then machines will be idle
This question can be answered more accurately if we know the cost of machining and of the operator

21. b : Independent operator activities (walking, inspecting, packing)
Human-Machine chart or Multiple Activity chart
a : Concurrent activity (both machine and operator work together: load, unload machines)
b : Independent operator activities (walking, inspecting, packing)
t : Independent machine activities
(automatic machining)
(a+b): Operator time per machine: time an operator devotes to each machine
(a+t): Machine cycle time (repeating time): time it takes to complete a cycle
L: Loading
T: Walking
U: Unloading
I&P: Inspection & Packing
Ideal worker-machine assignment:

22. Cost per unit produced during a repeating cycle of a combination of m machines and an operator.
If <1 then TC(n)<TC(n+1), n machines should be assigned
If >1 then TC(n)>TC(n+1), n+1 machines should be assigned