The following describes the process of simulating, creating and removing workload. It also provides examples of how workload, remaining workload, planned start and completion dates and overlapping operations are calculated.
Workload creation
Workload is created automatically at the creation of manufacturing orders, but it can also be created manually from the following programs:
- Supply plan calculation. See Create orders from a supply plan for more information.
- Material requirement calculation (MRP)
- Work centre capacity creation
Note: Workload is only created for work centres for which the Workload planning field is set to YES.
Workload removal
Workload is automatically removed at operation reporting or when a manufacturing order is closed. Depending on the Write down method defined for the work centre, workload will be removed in the following way:
- Write down method = 1 (reported quantity):
All internal set-up time will be removed when reporting the operation for the first time. Remaining workload time will be removed according to the following calculated percentage:
(Approved qty + Rejected qty) / Order qty - Write down method = 2 (reported time)
Workload will be removed according to the reported times of either run/labour or machine and internal set-up time. This is governed by the value in Workl planning type in the Work centre file. Internal set-up time must be reported for the operation if it should be removed.
Workload restrictions
Workload restrictions can be added to a work centre. The restrictions are defined in a group that is connected to the work centre. This information is used in the work centre capacity maintenance and in the manufacturing order planning (create/re-schedule manufacturing orders) to control if the date is valid for planning a specific product.
In order for workload to be planned for a manufacturing order, the specified restriction values must match the values on the manufacturing order parent item or operation. If none of the defined restrictions match the manufacturing order in question, the work centre may not be used for that order.
Note: This functionality is only available if the MFP (Finite planning) application is installed and activated.
Note: See Set up a workload restriction group and Add workload restrictions to a work centre for more information.
Calculations
The following sections provide examples of how workload, remaining workload, planned start and completion dates and overlapping operations are calculated. Click to expand each.
Workload
The following describes how workload is calculated. Depending on the Workload planning type set up in the work centre, the workload is either the sum of run/labour time and internal set-up (Workload planning type = 1), or machine time and internal set-up (Workload planning type = 2).
Example of workload for a bill of routing:
| Operation number | Queue time | Set-up time | Run/labour time | Transport time | Total workload time |
|---|---|---|---|---|---|
| 10 | 4 | 5 | 12 | 17 | |
| 20 | 10 | 10 | |||
| 30 | 6 | 5 | 6 |
Note: Queue and transport times are only used for the calculation of planned start and completion dates, and do not therefore affect the workload.
Remaining workload
The following describes how remaining workload is calculated. Remaining workload is what is left when a specific operation does not use the total capacity of a work centre during a day.
If the operations in the bill of routing have different calendar capacity, the capacity that is available for allocation between the operations is calculated as a percentage. Capacity that is the base refers to the previous operation.
Example:
| Operation number | Capacity | Capacity per job | Workload |
|---|---|---|---|
| 10 | 8 | 6 |
Used time for operation 10:
| 6 / 8 = 0,75 (75% of the day is used) |
| Operation number | Capacity | Capacity per job | Workload |
|---|---|---|---|
| 20 | 12 | 10 |
Remaining time to create workload for op 20 the first day is 3 hours.
| (12 * 0,75 = 9, 12 – 9 = 3 hours) |
Planned start and completion date
The following describes how planned start and completion dates are calculated. The start and completion dates for operations and manufacturing orders depend on the following factors:
- Work centre capacity
- Calculated workload
- Queue and transport times
Note: Queue and transport times are omitted when calculating workload and planned start and end date for the operations, but they are included in the calculation of the planned start and end date for the manufacturing order or between operations.
In the following example, the planned start date of the manufacturing order is 011002 and the calendar capacity is 8 hours per day.
| Operation dates | Manufacturing order dates | ||||||
|---|---|---|---|---|---|---|---|
| Calendar date | Operation number | Operation time | Workload time | Planned start date | Planned completion date | Planned start date | Planned completion date |
| 011011 | 10 | 4 (queue) | 0 | 011011 | |||
| 011011 | 10 | 4 (set-up) | 4 | 011011 | |||
| 021011 | 10 | 1 (set-up) | 1 | ||||
| 10 | 7(run/labour) | 7 | |||||
| 031011 | 10 | 5 (run/labour) | 5 | 031011 | |||
| 20 | 3 (run/labour) | 3 | 031011 | ||||
| 041011 | 20 | 7 (run/labour) | 7 | 041011 | |||
| 30 | 1 (run/labour) | 1 | 041011 | ||||
| 051011 | 30 | 5 (run/labour) | 5 | 051011 | |||
| 30 | 3 (transport) | 0 | |||||
| 061011 | 30 | 2 (transport) | 0 | 061011 |
Overlapping operations
The following describes how to calculate start and completion dates for overlapping operations.
The overlapping type and value are defined in the bill of routing. The overlapping type can either be 1 (quantity) or 2 (percentage of workload time). If the overlapping value refers to a quantity, the next operation can start when a certain quantity has been produced.
The following example illustrates a bill of routing where the operations are overlapped in time:
| Operation number | Overlapping type | Overlapping value | Run/labour time |
|---|---|---|---|
| 10 | 2 | 50% | 12 |
| 20 | 14 |
Operation 20 can start when 50% of the operation time for operation 10 has elapsed (6 hours).
Note: Set-up, queue and transport times are not included in the overlapping calculation.
The following example illustrates the calculation of start and completion dates for overlapping operations. The calendar capacity is 8 hours per day.
| Operation dates | |||||
|---|---|---|---|---|---|
| Calendar date | Operation number | Operation time | Workload time | Planned start date | Planned completion date |
| 011011 | 10 | 8 | 8 | 011011 | |
| 20 | 2 | 2 | 011011 | ||
| 021011 | 10 | 4 | 4 | 021011 | |
| 20 | 8 | 8 | |||
| 031011 | 20 | 4 | 4 | 031011 |
Note: An operation that overlaps another cannot have an earlier completion date than the previous operation. If this is the case both operations will have the same completion date.
Calendar capacity
When calculating calendar capacity, the day capacity is retrieved from the calendar that is defined on each work centre. Remaining values are retrieved from the Work centre file.
The following formula is used for the calculation of (gross) calendar capacity:
| Calendar capacity = Day capacity * Number of shifts * Man factor |
Note: Replace Man factor with Number of machines in the formula if Workload planning type is set to 2.
Workload capacity
When calculating (net) workload capacity, the day capacity is retrieved from the calendar that is defined on each work centre. Remaining values are retrieved from the Work centre file.
The following formula is used for the calculation of operation times (set-up, run/labour, machine):
| Workload capacity = Day capacity * Number of shifts * Man factor * (Efficiency factor/100) |
Note: Replace Man factor with Number of machines in the formula if Workload planning type is set to 2.
The following formula is used for the calculation of queue and transport time:
| Queue and transport time = Day capacity * Number of shifts |
Workload per job
When calculating the workload capacity for a single operation, Resources per job in the work centre is used to reduce the total day net capacity to the maximum workload hours that can be loaded for a single operation for the day.
The following formula is used for the calculation of workload per job:
| Workload per job = Workload capacity * Resources per job / Man factor |
Note: Replace Man factor with Number of machines in the formula if Workload planning type is set to 2.
Enquiries and printouts
- Workload enquiry
Use this enquiry to view workload for work centres or department sections. Workload can be displayed on either day or week level and in run/labour or machine time. The workload enquiry also includes planned workload created from the MRP batch job. - Capacity clearance enquiry
Can be accessed from the Workload enquiry. - MRP pegging enquiry
Can be accessed from the Workload enquiry. - Workload restriction enquiry
- Requirement forecast workload report