Question Related to Traditional Approach

1.      Explain the relationship and differences between a module and a program.

A program is a set of modules that work together to perform all the required functions. A module is a relatively small set of statements that carry out a single function. 

2.      What is the purpose of the automation system boundary? How do you develop one?

The automation system boundary defines which processes are going to be automated within the computer system, and which processes are part of the environment, or manual system. The system boundary, although needed for both structured and object-oriented development, needs to be defined explicitly for the structured approach. The object-oriented approach already has the system boundary defined in the use case diagram. 

The automation system boundary is developed at the DFD fragment level or below, by defining which processes are manual and which are automated. The boundary line is a line between these two processes.

3.      What is a system flow chart used for?

A system flow chart is used to depict the overall flow of information and control in a total system that consists of several programs. 

4.      What symbols are used on a system flow chart?

The symbols include a rectangle for a program, a rectangle with curved sides or a disk for a file, a rectangle with a curved bottom line for a report, a circle with a tail for a file, a trapezoid for a manual operation, and an arrow or lightning bolt for a transmission or movement of data.

5.      What is the purpose of a structure chart?

A structure chart depicts the hierarchical structure of modules that make up a computer program. It shows the calling hierarchy as well as the data parameter that is passing between the modules. 

6.      What are the symbols used on a structure chart?

            The symbols include a rectangle for the module, a connection line or arrow for the calling structure, and small arrows with open circles for data couples or with black circles for flags.

7.      Explain transaction analysis.

Transaction analysis is the process of identifying a set of transactions (usually via DFD fragments) and developing a structure chart. Transaction analysis results in a structure chart with a calling structure to call a module for each transaction type.

8.      Explain transform analysis. What is meant by the term central transform?

Transform analysis is the process of taking a DFD diagram and converting it to a structure chart. Transform analysis is based on the idea of “transforming” an input data flow into an output data flow. The central transform is the central process that transforms the data.  

9.      What is the difference between afferent and efferent data flow?

Afferent data flow is the incoming data flow in a sequential set of process bubbles. Efferent data flow is the outgoing data flow from a sequential set of process bubbles.

10.  Explain module coupling and module cohesion. Why are these concepts important?

In structured analysis, modules are ideally defined and built to have low coupling and high cohesion. With low coupling, the only knowledge that one module has about another module is its input parameters and output fields. Like a black box, a well-defined module is built this way so that other modules do not have to know its internal workings. Module cohesion refers to the single purpose of a module. If a module carries out only one function, it is self-contained and easier to maintain.

11.  Describe how structure charts for three-layer architecture are different from those for all-encompassing programs that execute on a single computer system.

Structure charts for three-layer architecture show all three layers but may not include modules to handle all operational aspects of the application tasks (for example, the data access modules that are included within the data access layer). All-encompassing programs that execute on a single computer system will include all modules.