All material flow objects process discrete material units. Therefore in Tecnomatix Plant Simulation three different material units exists:

1. Entity:
   A entity is a simple object with a predefined size.
2. Container:
   A container can load multiple entities in x- and y-dimension.
3. Transporter:
   A transporter can load multiple entities and container in x- and y-dimension. Additionally it can move. Therfore it is extended by routing, failure and control attributes.

Enhance your simulation model

Task:

Create the following material units for the in-house production units:

1. Housing Cover
• Name: HousingCover
• Derived from "Entity"
• Overwritten symbols for states "Operational" and "Waiting":
  
2. Piston Rod
• Name: HousingCover
• Derived from "Entity"
• Overwritten symbols for states "Operational" and "Waiting":
  
3. Pneumatic Cylinder
• Name: HousingCover
• Derived from "Entity"
• Default symbols for states.

Step-by-Step:

1. Open your simulation model from the previous chapter.
2. Right-click on "Basis > MUs > Entity" in the Class Library on the left side of the window and select the context menu entry "Derive".
3. Double-click on the new class element "Entity1".
   Alternativ: Right-click on the new new class element "Entity1" and select the context menu entry "Open".
4. Insert "HousingCover" in the name field. Leave the rest unchanged and confirm the dialogue by pressing on the button "OK".
5. Right-click on the renamed class element "HousingCover" and select the menu entry "Edit icons..." (1)(see figure 1).
6. Deactivte the inheritance by explicity activating the overwrite mode (2).
7. Browse through the symbols "Operational" and "Waiting" (3, 4).
8. Re-paint the symbol for both states (5).
9. Repeat the procedure for the piston rod and the pneumatic cylinder.