Week 6 Use Case Diagram

This week we were learning use case modeling. It is an objected-oritented approach to model user requirements. The former diagram is a use case diagram created to illustrarte the behavior of shoes stock management system.
If we have drawn an enent table, it is easy to draw a use case diagram. But system analysists have to pretend that it is difficult to draw it. The users are going to pay money. We must prove our work is hard and valuable.
VP is a very useful tool to draw diagram. But it is complex for beginner to use it. I have never seen some of the functions it provides.

week 5 traditional approach and developing event table

In week 5, we were talking about SDLC in traditional approach. The data flow diagram is vital in the traditional approach. But it seems that system analysts do not like it. The main reason is DFD view the business process as a set and mechanistic hierarchy. Today, more and more business are becoming dynamic so that DFD can not define all business well.

I have tried to draw an level-0 DFD for an online sales system.

I also discussed event tables with my classmates. I found that most people were trying to add lots of events into the event table. Somebody's event table has more than 40 rows! I think it is good to view a system from different angles. But they are too ambicious. We are beginners and we are going to draw user case diagram and write user case narratives. It is just too complex if we add every thing into one system. Thus, I modified my event table and followed "CRUD". It is a very logic way to include all important events although it is not very flexiable.

week 4 mock interview and event table

In week4 , we had an interview with tutor. An draft event table is drawn here, the red words are unsure part of the event table, I am trying to improve the quality of event table.

Week3 requirement gathering and preparing interview

In week 3, we have stepped into analysis phase of SDLC and mainly talked about gathering information. We were also required to listen to an audio file and prepare interview questions about shoes stock management in a shoes store.

Requirement gathering comprises dertermining requirement, gathering information and validating requirement. At first galance, it seems that gathering requirement is an easy work, but it turns out to be fairly difficult and need significant effort. A system analyst cannot gather requirement well until he possesses of sufficient technical skills, comprehensive understading of business process and good communication skills. Peter said business people do not like IT people. If they do not trust you, they will not tell you the right things. I think peter's words address one aspect of communication issues. Peter also talked about his own experience about building a system for a stationary shop in a school. There was a problem with the sales database. Every sale was recorder twice. Peter checked the programe code and everything else but still cound not find the problem. Then he went to the shop and watch how people scan item and he found that people scanned items twice! This example imply that watch how people doing things is a effective way to figure out user's requirement.

We also started assignment 1 in week3. The assignment is buliding a shoes stock management system for a shoes shop. We were required to listen to an audio file and prepare questions for a mock interview. Assignment1a is mainly drawing an event table. After I listened to the audio, I found that the system required for stock management is simple. The owner of the shop only need some kind of system to manage inventory, deal with returned shoes and perform sales processing functions. For instance, zac wants to know the location and availability of each particular shoes and the system can help him record these imformation.

FIT2001 Week1&2 Understanding the nature of system analysis

As the title indicated, the goal of the first two weeks' exercise is to help student understanding the nature of system analysis. During the lecture, I have studied system analysis theoratically. The more theoratical, the more difficult to understand the nature of system analysis. However,if students can combine the theory with real world, we probably can have a better understanding. I think that's why the exercise of the tutorial is requiring students to analysis water supply system and food system. students were split into several groups and each group discuss about the two systems.

Everyone is familiar with the water supply system and the food system because they have significant impact on our daily life. But the question still remains: Do we really understand the water supply system and food system? First of all, what we have seen everyday is small part of the systems, a large amount of elements are functioning and interactiong behind our sight. In additional, the quality of our life has improved dramatically during the last a few decades. People are more concerned about the higher level activities rather then the basic activities. I have clicked the web link on the tutorial notes and I found an very interesting story. A mum asked her son, "where does milk come from?" The boy responded loudly, "From supermarkets!" This story is an extreme example to point out people's ignorance of basic systems. Furthermore, although water system and food system seem to be simple at first galance, they are becoming more and more complex along with the development of our society.

When I discussed with my gruop members, I noticed that we were leraning the water and food system in the same way like blind people learning an elephant. Everyone of us had different view of the systems and we were trying to construct the systems in our mind by combining everyone's view together. We also did lots of research on websites. However, it was absolutely a mass, we finally got lost in the systems. I think it is mainly because we were studying complex systems in an arbitary way, we were strongly depending on our instinct. We do need an effective and efficient approach to study system analysis.

As communication skill is vital for system analysists, our homework was to perpare an presentation for water supply and food system. My job was to perpare a presentation for food system in the view point of standard authorities. In order to conquer the difficulties I mentioned previously, I decided to study the food system succintly. People may ask me how can you understan a complex system succinctly? Well, my answer is we are not trying to build a real food system. I am a beginner, I can identitfy the key elements of food system and describe these key elements in detail. I compared a food standard authority in a small town with the food authority in China. I quickly identified setting standards and executing standards are the key elements for any food autority. Then, I could foucus my mind on these two single elements. During the presentation, I still kept the principle of succinctness. For instince, when I was talking about setting standards for farmers, I didn't tell everyone a food authority should make blah.....blah...blah... standards for farmers. It is very boring and inefficient! Alternatively, I told them a story :I always buy some lunchbox size apples in supermarkets and I found that the quality of the apples varies a great deal in different markets. " What is the implication?" I encouraged everyone to think. Then I told everyone it mainly because farms fertilized and irritated the same kind of apples in different ways. In order to ensure that the food in the market is of satisfactory quality, food authority has to make standards for fertilization, irritation, solid and so on.

I want to stop writing in here. I don't want to make it a long article. The last thing I would like to say is what I am going to write next week. When I finish reading the first few chapters of the textbook, I am going to write a summary or argument to refine my thinking. Because Newton's story taught me when I read giant's book, I must try to stand on their shoulder so that I can look further than the giant!