Understanding different processing times help you finding your next improvement opportunity. All these times are interconnected, and sometimes confusing, here we describe the most important 10 measures of time used in process improvement, although definitions are widely vary from organization to another, this summary may at least help you finding hot spots to start reducing waste time.
1-Open time:
The official work hours; including break time, Planned maintenance time.
2-available time:
Usually it’s the open time excluding break time and planned maintenance time.
3-Up time:
Active time during which a Process is ready to perform its intended function, opposite of downtime.
Uptime=Available time-Downtime
4-Down time:
The period of time in which a process is not functional due to unplanned event, down time includes machine breakdown, unplanned maintenance, waiting for material, waiting for operator, …. While setup time and change-over time are not considered as down time although they are non-value add.
5-Setup time:
The time required to prepare a process to be ready to function or accept a job, setup time is usually needed once a day.
Examples: start operating ovens, chillers, and air compressors
6-Change-over time:
The time required to prepare a process to change from producing the last good piece of the last batch to producing the first good piece of the new batch.
Examples: exchange of dies, bins cleaning, machines reconfiguration
7-Cycle time (Ct):
It’s the time required for some process to contribute producing one piece of product.
Or the time it takes to do one repetition of any particular task typically measured from “Start to Start” the starting point of one product’s processing in a specified machine or operation until the start of another similar product’s processing in the same machine or process.
8-Throughput time:
The summation of cycle time of all processes.
Th=Ct1+Ct2+Ct3+……..+Ctn
9-Lead time:
The total time between demand and delivery, including Throughput time, inspection time, move time, and wait time.
10-Takt time:
Also known as 'rate of customer demand' or 'pace of customer demand',
How often completed units NEED to come out the end of the pipe as established by customer demand,
Takt time= available time/customer demand.