20.10.08

Green Street Car Park Class Diagram


It's very interesting to see how this diagram differs from my previous effort at this diagram. I definately have today's seminar to thank. Firstly I now have a class to deal with the questioning of issuing cards, I added the "sense" method to the two barriers, removed the exit card scanner class and created a new class to deal with car park capacity.


I think I have managed to create a less muddled diagram at least which has a better overview of the system. Previously I had too narrow a vision of where the system boundries were.

A Fragment from the Data Dictionary for the green Street Carpark


Example of an Expanced Case Description

Use Case: Exit Car Park
Actors: Employee
Goal: To successfully leave the car park

Overview:
When a member of staff wishes to leave the car park they drive to the exit barrier. The barrier senses the presence of the car, rises to allow the employee to drive through and lowers when they have gone. After this it adds one to the number of spaces available in the car park.

Typical Course of events

Actor Action____________________System Action
1. Employee arrives at exit barrier_____2. Barrier senses a car present
_____________________________3. Barrier rises
4. Employee drives away___________5. Barrier lowers
____________________________6. A space added to available number

Alternative courses:
3. The barrier malfunctions and does not rise (the employee seeks assistance and the barrier is opened for them by car park staff)

Example of a Higher Level Use Case Scenario

Use Case: Card Problems
Actors: Employee, Reception, H.R.
Goal: To attempt to enter the car park.

Description:
When a member of staff arrives at the car park they observe the “Full” sign is not on. They approach the barrier and place their card in the card reader. Despite the fact that their card should be valid the reader does not recognize the card. The staff member discovers that their card is damaged. They go to reception where the receptionist checks with HR that they are a valid employee and then issues them with a functioning card

Use Case Diagrams for the green Street car park


I had worked through lots of Use Case diagrams prior to going into the class this week and it was great to be able to see new ways of thinking about the system after I thought I had gone over it all thoroughly. For example, I had not put nearly enough thought into the system of cards being issued, I had not thought about a scenario where a user’s card might be damaged or broken and thus not activate the card reader despite being valid and I had also not thought about the system for leaving the car park (having assumed it was the same as entering).

I am including some Use Case diagrams in this post. They show the “happy day” scenario for entering and leaving the car park and two others related to the car park system.

Green Street Car Park Noun Analysis


The seminar today was really helpful. I was really able to look at what I’d come up with from new perspectives and I saw lots of things that I’d missed out when I worked through the Car Park case study initially.

During my original work through I came up with the following nouns:

* Barrier
* Cards
* Card Reader
* Sign
* Signal
* Spaces
* Visitor
* Visitor’s Card
* Employee

From the class I realised that administration of the card system by the company was important – so classes like “reception” and “human resources” should be added. It was also interesting to think about how “employee” and “visitor” could be amalgamated into a single class as they will both effectively use the car park in the same way after they receive their cards.

13.10.08

GoGreen Bikes - the diagram (mark 1)


I have been working on the diagram for the GoGreen case study. My main worry about it is that I may have over-complicated the diagram as my noun analysis seemed to result in a smaller and simpler list of options.


My secondary worry is that I have confused how the data relates to other parts of the system, resulting in a confusing picture (especially the relationship between Customer, Record and Hire).


Normal and Special are supposed to be sub-classes of Bike. I also think Reception seems to have a lot of things to deal with. I woder if that should be broken up into smaller sections. Perhaps one about the issuing of bikes and one dealing with the return. Or split up into admin and transaction. I'll have to think about it.

10.10.08

GoGreen Bikes Case Study - Initial Models (post script)

Just a note.

I would really appreciate some feedback on the sketches :-)

GoGreen Bikes Case Study - Initial Models


I have been trying to create a model of the GoGreen Bikes system based on my earlier analysis. So far I have worked out a few whilst trying to figure out which classes were necessary for the system and which were not.


I have posted some sketches of them here (they are very basic as I did them in MS Excel and Paint but hopefully they will be able to get across my general ideas so far.

I am aiming to properly flesh out some of these with attributes and methods included and then work on a final one which I hopefully will post this weekend.

7.10.08

GoGreen Bikes Exercise - Part 1

I have been working on the GoGreen Bikes exercise today. I got the case study off of WebCT and had a go at finding the possible classes. My results were a bit mixed but what I did discover were that the most important classes were "Bike" and "Customer"...this may seem a little like a waste of time but the whole thing was quite helpful.

I had a hard time with the associations/relationship category. I'll have to remember to ask for some clarification next week.

Hopefully I will be able to produce a diagram which I can post. I think either tomorrow or Thursday.

6.10.08

Testing...testing...123...

Please don't mark this!

Just checking out how a blog works, I'm really happy I get to do this rather then an essay.

Hopefully this week I'll manage to:
a) get to grips with this blog so I can make it a bit more slick looking
b) post some stuff on my work on the GoGo Green Bikes case study

I'm really looking forward to seeing how this part of the assignment works out :-)