TASK 5.4

This task is to summarize the research paper "Automatic Transformation from Data Flow Diagram to Structure Chart". Researcher, Minyi Guo, emphasizes the importance of transforming data flow diagrams into structure charts during the software design phase.

This paper not only highlights the importance of the transformation but also the difference between data flow diagrams and structure charts and how they use transform and transaction analysis to bridge the gap thereby ensuring a smooth transition between software development phases.

From the paper, we understand that a data flow diagram is a natural tool for the analyis phase of the software life cycle. It is also a graphical network representing the processes and data interfaces of a system. On the other hand a structure chart is useful in design and implementation phases and is also a graphical tool for descibing the hierarchy of modules to be implemented as well as algorithmic relationships and communication links among them.

Guo then describes transform and transaction analysis in further detail. The main definition i captured from the paper was this:

"In transaction analysis there is a transaction center which captures an input transaction, determines its type and then processes it in the appropriate branch of the center while in transform analysis the input and output data streams of a data flow diagram are followed to determine the central portion of the system responsible for main transform of data."

Guo also mentions about structured analysis and structured design being the most popular and successful software development methodologies used in most CASE (computer-aided software engineering) environments.

However despite these methodologies being successful and popular, the process of transforming from software specification to design document is not only complex and diffcult but cannot assure correctness. Thus, a tool called CAST (Computer-Aided Specification Transformation) has been constructed to automatically translate requirement specifications into design specifications during the development phase of the software life cycle.

CAST consists of a description language, a rule base and an automatic transformation system. It accepts a software specification expressed in terms of data flow diagrams as input. Then the researcher mentions about how the CAST system actually works. In brief, data flow diagram is inserted, then translated into a structured language representation. After this is done, it is determined whether transform or transaction analysis would be used to produce structure chart. Once that is decided, a structure chart is formed, evaluated and finally displayed to Sc_file.

Now last main point discussed in paper is about problem identification. The paper emphasizes about the improvements that need to be made to the proposed techniques of using structured specification language and transformational algorithms. The main areas needed for improvement are efficient use of semantic information to improve quality of transformation and better description of structure chart evaluation criteria.

That's all....

It was a long article to read and took me time to understand. Hopefully this summary is good enough to cover the main points of the paper... :)