Qeiteri Armelle

In reference to our assignment 8 and 9, a System Analyst has three required skills to be considered. It includes the ability to work on the technical and business side and also the ability to handle people, which is the most important skill.

The systems analyst (sometimes called systems architect or systems designer) orchestrates the effort. He starts by interviewing users, teasing out what they need as opposed to what they want—the nice-to-have things usually cost more than necessary. He often uses modeling software to evaluate what-ifs.
System Analysts need good speaking and writing skills, too, so that they can explain their systems and give good instructions to their clients. They draw diagrams and charts to show how information will get into the computers, how that information will be processed, and how it will get to the people who need it.

As mentioned, System Analyst should have a broader knowledge on how to create a data flow diagram. He must analyze the process of the system first before doing the whole diagram. The system analyst is in-charge of describing the right processes and considered all necessary information about the system in order to come up with a more readable and internally consistent balanced data flow diagram. The detailed description of every symbol used in the diagram. He must know how the decision variables will be properly put on. And lastly, the system analyst should be the one responsible for when be the process of the system will end.

So let me describe how data flow diagrams really works.

Data flow diagrams is a modeling tool used to describe the transformation of inputs to outputs. It is graphic illustration that shows the flow of data and logic within the system. The model generally starts with a context diagram showing the system as a single process connected to external entities outside of the system boundary. This process explodes to a lower level DFD that divides the system into smaller parts and balances the flow of information between parent and child diagrams. Many diagram levels may be needed to express a complex system. Primitive processes, those that don't explode to a child diagram, are usually described in a connected textual specification.

Data flow diagrams provides an overview of what data flows in a system, what transformations are done on the data, what files are used and where results flow. It is a good documentation aid which is understood by both programmers and non-programmers (i.e., laypersons). As DFD specifies only what processes are performed and not how they are performed it is easily understood by a non programming
user.

What is a context diagram?

A diagram giving an entire system’s data flows and processing with a single Process (circle) is called a context diagram.

What do you understand by leveling of DFD?

A context diagram is expanded into a number of inter-related processes. Each process may be further expanded into a set of inter-connected sub processes. This procedure of expanding a DFD is known as leveling.

What is a physical DFD?

A physical DFD specifies from where data flows and who processes the data and to whom the processed data is sent.

In what way is physical DFD useful?

It is easy to develop during fact gathering stage of systems analysis. Such a physical DFD is easily understood by a lay user who can verify the DFD drawn by an analyst and tell whether such a DFD corresponds to a particular operation
taking place in an organization. Physical DFD is the starting point for developing the logical DFD.

Thus, with the given characteristic of a system analyst and defining the data flow diagrams, I could say that I still have to practice more in analyzing certain systems in order to create a more effective diagram. I still have to develop my ability to interpret diagrammatic presentations of work flow, and prepare computer block diagrams and flow charts. And also the ability to operate an on-line date entry terminal.

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