SYSTEM ANALYSIS AND DESIGN

45-878

System Modeling Exercise I

Due: September 20, 1999

 

Data Flow Diagram

Your consulting team is required to analyze the following narrative of a system for a client. You are then required to draw a Context Diagram and a Data Flow Diagram describing the various processes involved in the system using System Architect. If you discover that the narrative is incomplete, you may make up reasonable assumptions to complete the exercise.

 

Narrative

Maximum Software is a developer and supplier of software products to individuals and businesses. As part of their operations, Maximum provides an 800 telephone number help desk for clients who have questions about software purchased from Maximum. When a call comes in, an operator inquires about the nature of the call. For calls that are not truly help desk functions, the operator redirects the call to another unit of the company (such as Order Processing or Billing). Since many customer questions require in-depth knowledge of a product, help desk consultants are organized by product. The operator directs the call to a consultant skilled on the software that the caller needs help with. Once a consultant answers the call, he determines if this is the first call from this customer about this problem. If so, he creates a new call report to keep track of all information about the problem. If not, he asks the customer for a call report number, and retrieves the open call report to determine the status of the inquiry. If the caller does not know the call report number, the consultant collects other identifying information such as the caller's name, the software involved, or the name of the consultant who has handled the previous calls on the problem in order to conduct a search for the appropriate call report. If a resolution of the customer's problem has been found, the consultant informs the client what that resolution is, indicates on the report that the customer has been notified, and closes out the report. If resolution has not been discovered, the consultant finds out if the consultant handling this problem is on duty. If so, he transfers the call to the other consultant. Once the proper consultant receives the call, he records any new details the customer may have. For continuing problems and for new call reports, the consultant tries to discover an answer to the problem by using the relevant software and looking up information in reference manuals. If he can now resolve the problem, he tells the customer how to deal with the problem, and closes the call report. Otherwise, the consultant files the report for continued research and tells the customer that someone at Maximum will get back to him, or if the customer discovers new information about the problem, to call back identifying the problem with a specified call report number.

 

 

Using System Architect you should:

 

  1. Draw a Context Diagram for the system (30%)
  2. Your DFD should include data stores and external entities.

  3. Draw a Zero-Level Diagram for the system (50%)
  4. Please make sure that you choose an appropriate level of detail for the Zero-level diagram.

    Also, make sure that you define the appropriate parent-child relationship between the processes.

  5. Draw a Level-1 Diagram for any of the processes in the Zero-Level diagram (20%).

Again, please choose an appropriate level of detail. You may choose any of the processes in the Zero-level diagram for this part.

 

Please Note:

  1. Please pay attention to Data Elements within data flows. All data flows should have relevant data elements defined inside them. All elements also have to be defined, i.e. Definitions should exist for all the data elements that you use in the system.
  2. Make sure that you do not break the general rules of data flow programming. For example, an external entity cannot have a data flow to or from a data store.
  3. Make sure you maintain consistency of data flows when you go from the Context to the Zero-level diagram. The same applies when you go from the Zero-level to the Level-1 diagram.
  4. Your data stores must have appropriate data elements defined. Again, these data elements have to be defined (using the Definitions menu) elsewhere to maintain consistency.

 

Deliverables

For this exercise, you have to hand in:

  1. A diskette containing an exact copy of the Project1 (or Project2) directory in which your diagram files are stored. You must copy all the files from the directory onto the diskette. Please label the diskette and write down the names of all group members on the label.
  2. The Cross Reference Symbol Diagram report (look at the File-Reports menu for different options).

  

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