Intended learning outcomes: Differentiate between processor-dominated scheduling and material-dominated scheduling. Produce an overview on the use of the MRP II/ERP concept or of the lean / just-in-time concept compared to the processor-oriented concept.
Processor-dominated scheduling (PDS) is a technique that schedules equipment or capacity (processor) before materials. This technique facilitates scheduling equipment in economic run lengths and the use of low-cost campaign cycles ([APIC16]).
See also [TaBo00], p. 30 ff. The campaign principle outlined in Section 8.3.1 is an example of processor-dominated scheduling. Indeed, capacity management has priority over materials management for scheduling. Finite loading is used as the scheduling principle. Materials are planned according to the results of finite loading.
Processor-dominated scheduling is characteristic of the processor-oriented concept. It is typically used to schedule manufacturing steps within a process stage. However, the process industry does not use it in every situation.
Material-dominated scheduling (MDS) is a technique that schedules materials before processors (equipment or capacity). This technique facilitates the efficient use of materials ([APIC16]).
Material-dominated scheduling can be used to schedule each stage within a process train. Typically, the MRP II / ERP concept as well as the lean / just-in-time concept use material-dominated scheduling logic. In the process industry, they have their significance as well.
The problem in the process industry is to identify the point at which the processor-oriented concept replaces the other concepts. Figure 8.3.2.1 provides a simplified rule of thumb. This line of reasoning is similar to that followed in [TaBo00]. In addition, see also Figure 4.5.3.1.
| The MRP II / ERP concept or the lean / just-in-time concept may be used if |
| -- Materials are expensive related to manufacturing costs |
| -- There is overcapacity. |
| -- Setup times and costs tend to be negligible. |
| -- There is job shop production rather than line or flow shop. |
| The processor-oriented concept may be used if |
| -- Capacity is expensive related to costs of goods manufactured. |
| -- There are capacity bottlenecks. |
| -- The one-off costs for each lot produced are relatively high. |
Fig. 8.3.2.1 Use of the MRP II / ERP concept or of the lean / just-in-time concept compared to the processor-oriented concept.
Course section 8.3: Subsections and their intended learning outcomes
8.3 Processor-Oriented Resource Management
Intended learning outcomes: Explain campaign planning. Differentiate between processor-dominated Scheduling and material-dominated scheduling. Describe a nonlinear usage quantity and a product structure with loops.
8.3.1 Campaign Planning
Intended learning outcomes: Explain campaign planning using an example of a process chain in chemical production. Identify campaign cycles for the example and a minimum campaign of one day’s production.
8.3.1b Synchronizing Process Stages
Intended learning outcomes: Describe how the process stages could be synchronized.
8.3.2 Processor-Dominated Scheduling versus Material-Dominated Scheduling
Intended learning outcomes: Differentiate between processor-dominated scheduling and material-dominated scheduling. Produce an overview on the use of the MRP II / ERP concept or of the lean / just-in-time concept compared to the processor-oriented concept.
8.3.3 Consideration of a Nonlinear Usage Quantity and of a Product Structure with Loops
Intended learning outcomes: Present the quantity of a manufactured product P as a nonlinear function of the usage quantity of a resource R. Identify possible solutions of issues entailed by a nonlinear usage quantity.
