How to Calculate Process Cycle Efficiency

Thanks for explaining this so well. I also use IGrafx to make value stream maps but will admit I really never knew how they got their PCE values.

Available time
if at work for 10.5 hrs:

Time is deducted for;
Smoko breaks: 3 x 10 minutes
Lunch: x 30 minutes
Wash – up: x 5 minutes
e.g. 10.5hrs x 60minutes = 630 minutes

= 630 min – 30min – 30min – 5 min
Available time = 565 Minutes
Available time = 565 x 60 = 33,900 seconds
= 33900/3600 (60 mins x 60 secs)
= 9.4 hours available

Takt Time
The pace at which the customer requires products if available time is 9.4 hrs.

Calculating Takt time
Our total time available = 9.4 hours (converting to seconds)
And customer demand = 777 products

How we calculate Takt Time:
Takt Time = Available time/Customer Demand
Takt Time = 9.4 hours x 60 minutes x 60 seconds/777 products
= 33,840/777
Takt Time = 43.5 secs

Uptime if 93% – determined through OEE
This is the amount of available time we can realistically expect to utilize e.g. uptime is 93 %, we set a target to achieve 93% or better for every process, assembly, machine and piece of equipment in the factory.

Therefore, 93 % x 43.5 = 40 seconds

Number of Staff Required

Takt time per workload at each workstation will be at the rate of 40 seconds.
After calculating Takt Time and uptime, work content time needs to be established from point A to point B.

Total work content time divided by Takt Time will give you the number of staff required to produce the number of products by customer demand.

Number of staff = Total work content time/Takt Time

= 460 seconds/40 seconds

Number of staff = 12 staff required

Cycle Time
The pace at which we produce products to ensure we meet the customer demand. The total time taken for the whole process from start to finish and then start again.

Once staff requirements are finalised, all workstations must be cycled timed and a Yamazumi board needs to be set up to balance all workstations to Takt Time using a stopwatch.
For example: Point A starts from station 1 to Point B at station12.

12 staff required to meet customer demand

Yamazumi
It is a stack up bar chart that shows the balance of cycle time workload between numbers of operators typically in an assembly line.
It also is a load chart that breaks down the individual work tasks, representing the time taken. If it is kept up, as Kaizen; Continuous Improvement is applied. The strips representing the tasks are updated (trimmed) so the timing is more or less accurate. Best represents a combination with a cross training chart that shows who can perform which tasks, as they are specified, in the time that is specified.
It allows easy balancing on an assembly line to get every operator doing the same amount of work. It also allows easy “re-balancing” when the Production rates change up or down.