Analyzing Processes
Process Diagram:
(e.g. Producing Contact Lenses) hold Data information flow

Other Common Process Measures • Cycle time
– Average time between completion of successive units by the process – Reciprocal of throughput rate

Process Layout of a Medical Center – Capacity Analysis
Patient Type A B C D Total Patient Mix Wait Area X-ray 0.4 1 1 0.3 1 0.2 1 1 0.1 1 1 1 0.7 1000 400 571 Department Orthopedic Cardinology Neurology Intensive care 1 1 1 1 1 0.4 0.3 0.2 0.4 250 625 500 1667 300 1500 600 1500

add value

Utilization =
Load Factor =

Actual Output Rate Maximum Throughput Demand Rate Capacity

Dept. capacity

Four General Categories of Production Processes
1. 2. 3. 4. Continuous Flow Process Line Process Batch Process Job Shop

Max. # of total 1000 patients arrived before reaching cap.

Variability: Classic Queuing arrival rate () in customers/hour • service rate () in customers/hour (avg. time for one customer = 1/) • # servers = s Therefore, capacity = _s*_
•

Physics of Queues: M/M/1 system
Performance Measures: Utilization:  Average time in system = /( Average number in system =  /( Average time in line = 1/(  Average number in line = 1/(  Probability of no waiting = 1 – 

Process Choice at King Soopers Bakery
• Bread process
– Flow process – High volume – Difficult and expensive to change capacity

Servers (s)  customers/hr./server arrivals ( customers/hr.) departures queue system

• Pastry process
– Batch process – Moderate volume and moderate automation

• Custom Cakes
– Job Shop – Low volume, and high skilled labor

Curse of Variability
Saturation Effect – Under variability, as utilization approaches 100%, the avg. number in the system approaches infinity
Flow Time

Capacity Cushion
• Capacity utilization < 100%
– Demand and process