How to use ‘Shifts’
A “shift” is a timeframe where a team of people is operating a (set of) machine(s). Each machine will have one or more shifts designated. Here you will define the “masterlist” of shifts. When changing a shift name here, it will be changed anywhere it was used in your OEE calculations.
The use of Shifts
If a company uses shift work, these shifts can be named. Furthermore, for each shift a normal start time and shift length (the interval) needs to be defined (e.g. 480 minutes, 510 minutes). When calculating the OEE, usually per shift, this is also the length of the OEE calculation (of course, the duration can be adjusted manually per occasion).
Make sure you define all regular and frequently occurring shifts e.g. [Short Fridays, 300 minutes]. With this information, differences in effectiveness between e.g. day and night shifts can be analyzed.
The use of different shift models at one machine
What to do when multiple shift models occur on a machine?
Imagine, during the first half of the year the opening time could be 460 min per shift for machine “XY” and during the second half, the opening time could be 500 min per shift for the same machine.
This assumes the user has to define an opening time of 460 min during Q1 and Q2 then, the first of July, he has to redefine the opening times.
If -per actually performed shift- the correct opening time has been used and accounted for, this is not influencing the OEE calculation. How to proceed in this case?
You could either change the values in the shift table twice a year or you might define i.e. [Long Night 500] and [Short Night 460].
In the first 6 months you will have to enter a total of 460 minutes and later a total of 500 minutes. For the calculation theoretically there is no difference. When running longer, more output would be expected and more will come out, so the ratio between what could come out and what really comes out will stay the same.
In real live there might be a slight difference i.e. due to fatigue, or the fixed warming up period of the equipment (that weighs more when the shift is shorter). The year-graph in such cases might show a ‘season’ pattern. This is not a statistical disturbance but a phenomenon, that you will have to study and learn about. Since OEE over a longer span of time is a weighted average, statistically this is not a problem.
How to use different shift-patterns and plan shifts with teams
When using different shift patterns and want to plan teams to shifts at machines on specific dates, you need to configure the optional Shift Planner: a powerful tool to plan and schedule your machines and teams in upcoming shifts. (more about the Shift Planner)
Configuring a shift
|Name||Enter a unique name for the shift as used by the production team.|
|Start time||If the shift is supposed to start at- or around a certain time, enter this time here and check the checkbox. The start-time will be used to check valid start-time at data-entry. Uncheck the checkbox if any start-time is OK for this shift|
|Duration||If the shift has a default duration: check the checkbox and enter the duration, e.g. 510 min. During data entry, the software will check whether the total amount of registered time equals the expected shift length. If the duration is allowed to be variable, uncheck the checkbox. Any registered time will be accepted during data entry|
|ERP number||Reference number to identify this shift in other software e.g. SAP|
|Cost factor rate||This indicates a cost factor rate for example a night shift might be more expensive than a day shift|