Intended learning outcomes: Present the cumulative resource profile of an order as well as cumulative load and capacity before loading the order. Explain rough-cut planning of the cumulative load and capacity after loading the order.
Rough-cut finite loading corresponds to finite loading, but it is based on the resource profiles for rough-cut work centers presented in Section 14.4.1.
If order due dates are flexible or if variations in capacity are undesirable or unfeasible, we can also use planning with rough-cut finite loading. In this case, order-oriented techniques are relatively simple, since rough-cut planning places the emphasis on approximate, rather than exact maintenance of capacity. The sum of any over- and underloads should then be smoothed out over a sufficiently short time horizon.
It is always the cumulative capacity and cumulative “preload” that are considered. We also create a cumulative resource profile for the new order to be loaded. As an example, Figure 14.4.3.1 shows such a profile for one rough-cut work center. The important variable here is the cumulative load at the end of the profile.
Fig. 14.4.3.1 Cumulative resource profile.
Figure 14.4.3.2 compares cumulative capacity and cumulative “preload” and yields the following result for the new order.
Fig. 14.4.3.2 Rough-cut planning: cumulative load and capacity before loading the order.
- The earliest start date is the period with the first available capacities that will not be used in subsequent periods.
- The earliest completion date according to available capacity is the end of the period in which, for the first time, the available capacity permanently exceeds the cumulative “preload” plus the cumulative load for the order, that is, in which the available capacity is not less than this total.
Figure 14.4.3.3 also shows the newly loaded order.
Fig. 14.4.3.3 Rough-cut planning: cumulative load and capacity after loading the order.
- The earliest completion date is the maximum total of the earliest completion date according to available capacity and the completion date obtained by adding the lead time to the earliest start date.
Capacities will be locally underused or exceeded. If the overload or underload frequency is relatively intense, that is, continues over just a few periods, it can be compensated by means of control of operations. This is possible because we are dealing here only with rough-cut structures. The same applies to long-term infinite loading as described in Section 14.4.2, in this case simply because the loading is long term.
Course section 14.4: Subsections and their intended learning outcomes
14.4 Rough-Cut Capacity Planning
Intended learning outcomes: Describe rough-cut network plans and load profiles. Explain rough-cut infinite loading and rough-cut finite loading.
14.4.1 Rough-Cut Network Plans and Load Profiles
Intended learning outcomes: Present an example of a rough-cut network plan with two rough-cut work centers. Explain the resource profile of both rough-cut work centers as well as the resource profile for the combination of the two rough-cut work centers.
14.4.2 Rough-Cut Infinite Loading
Intended learning outcomes: Present an example of a resource profile for one rough-cut work center. Describe the result of rough-cut capacity planning with deferred completion date.
14.4.2b Rough-Cut Infinite Loading — Example with two Rough-Cut Work Centers
Intended learning outcomes: Explain rough-cut capacity planning with two rough-cut work centers and the result after moving the completion date of one operation.
14.4.3 Rough-Cut Finite Loading
Intended learning outcomes: Present the cumulative resource profile of an order as well as cumulative load and capacity before loading the order. Explain rough-cut planning of the cumulative load and capacity after loading the order.
