Phased Modeling Approach

Instead of trying to build a model all at once, you may want to implement a phased modeling approach where you build the model in stages. This will help you understand the basic modeling elements before moving on to more complex ones like attributes and IF-THEN logic. The following elements are those components normally entered during each phase of the model building process.

Phase 1: Basic Model Elements

In the first phase you input all of the basic model elements: General Information, Locations, Entities, Arrivals, and Processing. You also import a background graphic to help in placing the locations in the layout window. Upon completion of this phase you have a fully working model, ready to animate and collect output.

Phase 2: Adding Resources & Variability

The second phase normally consists of expanding the model by adding resources and the corresponding path network needed to move entities, using resources, from location to location.

Phase 3: Additional Operations

The final phase usually consists of adding additional reality to the model—that is, adding those nuances that make the model an accurate representation of a real system. These include:

• Adding Quantity and Time_in_system attributes.

• Changing operational times from simple time constants to distributions.

• Adding features that ensure accurate entity processing.

• Adding variables for on-screen display.

• Defining appropriate downtimes.