Construct a Context Diagram, Function Decomposition & Data Flow Diagrams (Level 0 and level 1 only), Use case and activity diagrams based on the case study described below. There should be one level 0 diagram only, and for each function/process defined in the level 0 diagram, one level 1 diagram is required. (Might be pushing it to get a full set of level ones with the amount of information you have given them. You might consider asking for a couple of level 1 diagrams.)
All diagrams must be computer generated using VISIO tools and balanced in conformance to the rules and standards specified in lectures and tutorials.
Acme Garage—Case Study
The Acme Garage specialises in repairing cars. Before they fix a car they always check to see that the customer has paid for work done previously. Customer details are kept in a Customer file and details of each job are kept in a Job file. Kim works in the office and maintains (Create, Retrieve, Update, Delete) the Customer database. The mechanics (Bill and Ben) write the entries into the Job book. During the process of fixing a car parts may be required. Acme need to keep a stock of frequently used parts (eg spark plugs, oil filters, air filters) these parts are purchased regularly from suppliers and Acme is then invoiced. Less frequently used parts are ordered as required. Once they have a good supplier they tend to stick with them so they only ever have one supplier for each part. Reference to the Stock file will indicate if parts required for a particular job are in stock otherwise the parts will have to be ordered in. In the case where items are removed from stock the balance of stock needs to be reduced. The Stock file takes the form of an Excel spreadsheet and is also maintained by Kim. In the case where stock is ordered the details of the order are recorded in the Order file (in a filing cabinet), the cost of the parts is added from the invoice that is received when the parts are delivered. After the job is completed the hours of labour are recorded in the Job file and the Stock file and the Order file will be used to determine the price of the parts used which will also be recorded in the Job file. The contents of the Job record are then used to produce an invoice that goes to the customer. Customers are required to pay in full in 30 days; if payment is not made a letter of demand is sent and a 10% penalty is applied to the account.
Supplies are regularly ordered from suppliers whose details are recorded in a Supplier file (also kept in the Access database). A copy of all orders is stored in the order file and when invoices are received they are checked against the goods received and then are attached to the order. At the end of the month these invoices are paid in full.
Most of the data entry involves simple business transactions (receiving payments, making payments). Periodically new customers, or suppliers are added to the database. Acme has regular dealings with its bank and also sends in Tax Return each year. The information for the Tax Return comes from records of receipts and expenditure. Depreciation of equipment is claimed on the income tax return. The information for this part of the Tax Return comes from an asset register that contains details on all the equipment owned by Acme. Any new equipment purchased from a supplier must be recorded in this register. A variety of information is extracted from the system through inquiries and the generation of periodic reports. This information is used by Gloria, the owner of the garage, to manage the business. An unpaid invoice report and an unfilled orders report are generated at the end of each month.