Operator and machine time per step.
Use it when one operator runs machines with automatic cycles. It plots manual, machine, walking and waiting time per element against takt, so you can see whether the cycle fits and where the operator stands idle.
Manual is operator work. Auto is machine time that starts when the manual part ends. Walk follows the manual part. Y means the operator waits for the auto time to finish before moving on.
Operator time runs element by element. Cycle time is the later of the operator finishing and the last machine finishing. Waiting is shown in red where the operator stands by for an auto cycle.
The standard work combination chart (sometimes called a combination sheet) maps one operator's sequence of steps over time, separating manual work, automatic machine time and walking.
An operator loads a lathe (8 s manual), starts it (35 s automatic), walks 4 s to a deburr station, deburrs a finished part (18 s) and walks back (4 s). The total manual and walk time is 34 s within a 45-second takt, and the lathe's automatic cycle finishes while the operator is away, so there is no waiting.
To design and check one operator's work sequence so that manual, machine and walking time fit within takt time.
Takt time, the work sequence and standard work-in-process (the minimum parts needed in the cell).
Observe the job and time each step several times with a stopwatch time study, then use a typical repeatable value.