Intended learning outcomes: Calculate, in a rough-cut network plan, the earliest start date and the latest start date for each operation. Determine the resource profiles as well as the load and the deferred earliest completion date for the operations without overloading the capacities.
Figure 14.7.3.1 shows the network plan for a production order.
Fig. 14.7.3.1 Rough-cut network plan with two rough-cut work centers.
a. Complete the network plan: Calculate the earliest start date and the latest start date for each operation. What is the lead-time margin (the slack time), and what is the critical path? Determine the slack of all operations not on the critical path.
b. Following the technique introduced in Section 14.4.1, determine the resource profiles for rough-cut work centers 1 and 2, as well as the resource profile for the combination of rough-cut work centers 1 and 2.
c. Figure 14.7.3.2 shows the preload of rough-cut work center 2. Load the resource profile for rough-cut work center 2 with infinite loading. Determine the earliest completion date for the operations of rough-cut work center 2. Further, determine the load and the deferred earliest completion date for the operations of rough-cut work center 2 without overloading the capacities.
Fig. 14.7.3.2 Preload of rough-cut work center 2.
Solutions:
a. Lead-time margin is 1. Operations 1, 3, 6, 8, 10, 11, and 12 make up the critical path. Operations 2, 4, 7, and 9 could be deferred by 4 time periods, operation 5 by 7 periods.
b. The figure that follows shows the results for rough-cut work center 2 as well as for the combination of both rough-cut work centers 1 and 2. The length of the arrow indicates the number of time units for a possible deferring of the start date of operations not on the critical path.
c. The earliest possible completion date for the operations of rough-cut work center 2 using infinite loading is — as the above figure shows — at the end of period 14. For finite loading, the next figure shows the result: an earliest possible completion date at the end of period 15. Note: Because operation 9 is not on the critical path, parts of its load can be deferred to later periods in order to prevent overload.
Course section 14.7: Subsections and their intended learning outcomes
14.7.1 Exercise: Capacity Determination
Intended learning outcomes: Determine theoretical capacity, availability, rated capacity, demonstrated capacity, actual utilization, work center efficiency, etc.
14.7.2 Exercise: Algorithms for Load Profile Calculation
Intended learning outcomes: Explain load profile calculation extending across several load periods.
14.7.3 Exercise: Rough-Cut Capacity Planning
Intended learning outcomes: Calculate, in a rough-cut network plan, the earliest start date and the latest start date for each operation. Determine the resource profiles as well as the load and the deferred earliest completion date for the operations without overloading the capacities.
14.7 Scenarios and Exercises
Intended learning outcomes: Determine capacity. Execute algorithms for load profile calculation. Elaborate an example for rough-cut capacity planning.
