**2.2 Decision-making in production planning and control**

Moreover, also, within PPC human decisions undergo the suggested phases of the DMP models. Typical decision-making situations of PPC are shown in **Figure 1**.

PPC contains two subprocesses which are production planning and production control. These two subprocesses contain several task functions which require several decisions. Production planning focuses on the development of the basic concept to determine when to produce what in which quality. Production control has an overall monitoring function to achieve the production targets by the use of different control techniques.

P*roduction program planning* encompasses several decisions about the production sequence and the required materials. Based on this, *quantity planning* determines production quantities and lot sizes. *Due dates and capacity planning* contain several decisions concerning capacity plans and due dates for specific production steps. The *order release* marks the starting point for the production. Since disturbances, such as machine breakdowns, delays in material supply, or quality problems, may occur during production, a continuous *order monitoring* is accomplished. The necessary decisions within these main tasks of PPC are often complex and require the consideration of several parameters. Thus, in PPC typically decision-making is usually supported by DSS. DSSs are often self-developed by using case tools like Crystal, Analytica, or iThink for the development.

#### **2.3 Insufficient design guidelines for decision support systems**

While there is a lot of research on DSSs in general (e.g., [12]), as well as on several components and modules of DSS (e.g., [13]), there is only little research about standardized design guidelines for DSS. For instance, [6, 9] criticize the lack of an integrated framework to support a standardized design of DSS. However, [9] propose a framework as the basis for standardized guidelines for DSS designers.

**Figure 2** shows the framework suggested by [9]. The framework contains four levels. (1) The first *decision-making level* is based on the original DMP model of [8] and on its extensions containing all five steps within the decision process. (2) The second *decision service task level* focuses on tasks which require human intelligence and is based on a task-method-subtask structure to infer logical conclusions from the analyzed data. (3) The third *architectural capability level* considers user interface, data information knowledge, and processing capabilities. (4) The fourth *computational symbol-program level*

**Figure 2.** *DSS design framework with adaption according to [9].*

focuses on specific computational mechanisms based on artificial intelligence techniques such as computer-based reasoning (CBR), rule-based system (RBS), etc.
