Product, Process, & Schedule Design
Dr. Rosario Rosas-Vega
IE 4355 : Facilities Design
Texas State University
Schedule Design
Schedule design decisions provide answers to questions involving how much to produce and when to produce.
Production quantity decisions are referred to as lot size decisions.
Determining when to produce is referred to as production scheduling.
How low production will continue?
Impact of Schedule Design
1. Machine selection
2. Number of machines 3. Number of shifts
4. Number of employees 5. Space requirements 6. Storage equipment
7.
Material handling equipment
8.
Personnel requirements
9.
Storage policies
10.
Unit load design
11.
Building size
Schedule Design
Process Requirements
Process design determines the specific equipment types required to produce the product. Schedule design determines the number of each equipment type required to meet the production schedule Specification of process requirements typically occurs in 3 phases:
1.
2.
3.
Quantity of components to be produced including scrap Equipment requirements for each operation
Combine the operation requirements
Calculation Production Requirements
Ik
Operation k Ok= Ik (1-dk) dkIk
Let:
dk = percentage of defective items produced on the kth operation. Ok = desired output without defects
Ik = production input
On the average:
For products with n sequential operations:
Example
• A product has a market estimate of 97000 components and requires three processing steps (turning, milling, and drilling) having scrap estimates of d1=0.04, d2 =0.01, and d3=0.03. What is the expected number of units to start
2
3
O3
production.
I1
1
Ik = Ok /(1-dk)
I3 = 97000 /(1-0.03)=100,000
I2 = 100,000 /(1-0.01)=101,000
I1 = 101,000 /(1-0.04)
=105,219
OR:
I1 = On /[(1-P1) (1-P2)…(1-Pn)]=
I1 = 97000/[(1-0.04) (1-0.01)(1-0.03)]=105,219
Productions Requirements with Rework
Example
The end product requirement is 100,000
pieces.