A rough cut capacity plan involves resource requirements planning. RRP is a way of checking that the manufacturing plan is feasible, i.e., whether there is enough capacity to fill all shop orders. RRP means long-term planning without respect to details. The goal of RRP is to balance resources that take a long time to change against existing demand. In other words, RRP means checking how well production will meet the manufacturing plan, based on the master schedule and the entered resource requirements.
Resource requirements planning helps you plan the following:
The work centers to be used have the following capacity:
| Work Center | RRP-A | RRP-B |
| Units of Measure | Hours | kg |
| Crew Efficiency | 100% | 100% |
| Qty per Day | 100 | 10 |
The part to be manufactured, RRP-1, has two different operations as follows:
| Operation | 10 | 20 |
| Work Center | RRP-A | RRP-B |
| Fixed Resource Consumption | 5 | 0 |
| Resource Consumption Code | Units per part | Parts per unit |
| Variable Resource Consumption | 10 | 0.1 |
| Crew Efficiency | 100 | 90 |
In the example, a quantity of 10 of part RRP-1 is needed on a specific date.
RRP starts by calculating operation 20. The work center can process 10 units per day.
The operation duration is only one day, since the work center can process 10 units per day and the operation takes only one work center unit to complete 10 units. Even though the work center has only a 90% efficiency factor, the operation does not require more than 1.11 units, which is well within the capacity limits. On this day, the operation accounts for just over 10% of the work center's workload.
For each separate demand, RRP burdens the work centers with their full capacity every day until the demand is met. RRP ignores all other previously-entered demands. This means that there can be conflicts if a work center is planned to 200%.
Next, RRP calculates operation 10. The work center can process 100 units per day.
The operation length is 2 days, since the work center has a capacity of 100 units per day and the operation takes 100 work center units to complete 10 units of the part. The extra day is needed because the setup time is 5 units from exceeding the capacity limit of the work center.
This operation results in one day's 100% workload and one day's 5% workload.
Consider a work center with a capacity of 10 units.
For a single demand that needs 50 units with a due date of Friday, resource planning burdens the work center with 10 units per day from Monday through Friday. This means that each day has a 100% workload.
On the other hand, if there are 5 separate demands for 10 units each, all due on Friday, RRP plans all requirements for Friday. This means that the work center has a workload of 500% on that Friday and none on the other days of the week.