This document explains the process of determining in detail the amount of labor and machine resources required to accomplish the task of production.
Capacity may be created on different levels using different parts of M3. If capacity is created on a aggregated level or a product line level, Resource Planning is used. If capacity is created based on the Master Production Schedule, Rough-cut Capacity Planning is used.
The load and the capacity have been compared and adjusted to match each other. You know if capacity is insufficient during specific time periods.
The CRP-results are input to further planning using manual and auto scheduling.
The following prerequisites must be met:
Capacity Requirements Planning interacts with other parts of M3 according to the illustration below:
Released and planned orders created from manufacturing, maintenance or customer orders are the basis for creating load in the system. Load is normally created automatically but can also be manually created for planned orders.
In 'Manufacturing Order Type. Open'(PMS120), the user decide whether planned orders will automatically generate load. If the load should not be automatically created it can be manually created by 'Load. Create for Planned Orders' (CPS050).
Load can also be calculated for orders in past time by using 'Load. Create for Past' (CPS930). When running this, the load for the past time orders will be grouped together and placed either on the present week's load or the previous week's load. This is controlled from 'Settings - Capacity Planning' (CRS786).
Infinite/Finite capacity scheduling
Infinite/finite capacity scheduling is used to determine whether overload can be created for the operation in connection with the calculation of start and/or finish times for an order.
A bottleneck is a facility, function, department, or resource whose capacity is less than the demand placed upon it. For example, a bottleneck machine or work center exists where jobs are processed at a slower rate than they are demanded.
Bottleneck planning means that when a manufacturing order is entered with a chain of operations containing a bottleneck, all requirements planning will occur around this operation. The operations before and after the bottleneck will be planned in coordination with the bottleneck. The bottleneck operation is planned so that the entire operation time can be completed without a stop due to overloading.
Only one operation in a flow of operations can be set as bottleneck planned. This operation can be located in different places depending on the product. If it is placed first, a push strategy will be used to schedule the following work centers. If it is placed at the end, a pull strategy will be used to schedule the prior work centers.
In order to make bottleneck planning more practical upon entry of manufacturing orders, a simulation is run whereby a start date and completion date are calculated for the entire manufacturing order.
In 'Work Center Schedule. Open' (PMS230) the work center load is displayed. Here, orders can be split and rescheduled if the capacity is overloaded. The capacity/load display programs can also be accessed from here. The orders can also be scheduled to a set sequence between each other. This for instance, in order to minimize setup times.
Set whether the work center is man or machine oriented on the work center itself. This and the number of men/machines, shifts, utilization factor and normal daily capacity generate the total capacity per day. This capacity can be scheduled as infinite or finite. This is also controlled from 'Work Center. Open' (PDS010). Finite scheduling can also be handled as bottlenecks.
Planned and released orders can be automatically scheduled and/or sequenced by using M3 SWB.