Parallel Process
Two or more work centres performing the same process step simultaneously.
Also known as: Concurrent Process, Parallel Work Centers, Duplicate Resources
Parallel processes multiply the process rate by the number of work centres. Two clerks doing the same work can process twice as many units per hour as one. From the process perspective, more work gets done in less time.
However, from a single unit’s perspective, the process time doesn’t change. If one clerk takes 30 minutes to review an application, adding a second clerk doesn’t make each review take 15 minutes, it means two reviews happen at the same time.
Formula
Combined rate: Rcombined = r × number of work centres
Process time per unit: unchanged
Example
One work centre has a process rate of 15 units/hour. Adding a second parallel work centre: combined rate = 15 × 2 = 30 units/hour. Process time per unit is still the same, each unit still takes the same time, but two are being processed at once.
Why It Matters
Adding parallel capacity is the most common way to resolve a bottleneck. If the bottleneck step has a capacity of 10/hour and demand is 18/hour, adding a second worker at that step brings capacity to 20/hour, resolving the bottleneck.