Business Process and Flowchart Modeling

Process Modeling There seems to be some confusion on the modeling exercises. Allow me to explain a little.

First a warning. This explanation may help clarify or muddy the waters even more. ;-)

Processing modeling (object oriented modeling) is an iterative process. Starting with very high levels and working down to excessive details. Let’s look at the following process:

A customer enters the supermarket. The customer takes a shopping cart or basket and strolls through the supermarket. The customer selects items from the shelves and puts them in the shopping cart or the basket. When finished, the customer brings the items to the cash register. The cashier calculates the total price of the merchandise. The customer pays for the merchandise. The cashier bags the items, issues a receipt to the customer and, if necessary, returns the change. The customer picks up the bags and leaves the supermarket.

Context Activity Model: This is the highest level of activity modeling. The context diagram is a single activity showing inputs and outputs to a process. It represents the owner’s view of the process. For the process above the Context Activity Model could be as simple as:

Activity Model: In some modeling languages this is called a decomposition diagram. The purpose is to take the context model and add levels of detail. The following, might be a decomposition of the context model:

Purchase Goods

Potential Customer

Customer

Flow Chart: This is where we start taking the activity diagram and adding flow and decision points into the process. A simplified flow chart is shown below.

Gets Cart Potential Customer

Customer

Select Goods

Enters Checkout

Empty Cart

Full Cart

Get Cart

Potential Customer

Customer

Enters Checkout

Enter Store

Cart or

Get Basket

Walk Aisles

Selects Item

Finishe

Yes

No Basket

Cart

Swim Lane Diagram: Adding swim Lanes helps the analyst and designer determine where activities and decisions need to be made in a model. We do this by adding what we call “Actors” in object modeling language and aligning activities and decisions with actors.

Now you should be able to see how these models build upon one another. Each model adds some level of refinement and added detail. In many cases, you find some detail that will require you to go back and revise the previous models. That is expected.

I hope this seeing these various models in sequence adds to your understanding. These models continue to add detail until they become design specifications which are very detailed. If you are a BMIS major, you will see more models as you progress through your courses and you will see all of them come together in the BMIS 351 and BMIS 460 sequence of classes.