Individual assignment

The following assignment, issued in week 4, is to be submitted in week 8, and returned in week 10. Submissions are marked out of 100.

Collaboration and Plagiarism

Students are encouraged to collaborate wherever possible to encourage learning. For work that is assessed on an individual basis, it will be normal practice for collaboration to cease prior to actual work on the item to be assessed. Plagiarism is the unacknowledged use of the thoughts, writings, or inventions of others. This includes software design and code. Plagiarism is regarded as misconduct by the University and will normally result in disciplinary action. You are urged to read the University’s official statement on cheating (including plagiarism). Related information is also available in the booklet “Examination arrangements, information and guidance for candidates” which you will receive prior to taking examinations. If you are in any doubt about how the statement applies to examinations or CAs for particular modules, please consult your tutor.

WYSKA, 2003 edition

Read the following text of a change request for the API for a Supermarket Controller:

The supermarket is to issue a discount card to selected customers. The card can be read by a card reader attached to the checkout. If the card is read at any time between StartBill and EndBill, the checkout sends a StartCustomer signal to the store controller, together with the number from the card. At present the number is not used by the store controller. If the card is swiped through the card reader after EndBill or before StartBill, it has no effect. Swiping the card a second time has no effect. When the EndBill key is pressed, the store controller causes the checkout station to print the bill, but the prices charged are discounted. The amount of discount is a percentage of the price of the item. When the warehouse manager adds a line, the value of the discount, which can be 0, 10, 20, or 50, is specified as an extra parameter on the AddLine command. There is a new operation for the warehouse manager, SetLineDiscount, which has a line number and a discount value as its parameters.

Make a list of all the changes necessary to the following documents to implement this change:

API for a Supermarket Controller: Analysis Document, Document E02, issued 5 October 2004 (40 marks)
API for a Supermarket Controller: Specification Document, Document E03, issued 11 October 2004 (60 marks)

The changes should be specified as follows:

For each change to the text of a document, identify the text to be changed, and supply the replacement text.
For each addition to the text of a document, specify the place where the new text is to be added, and supply the new text.
For each change to a diagram, identify the part to be changed, and describe the change required. Include a sketch if it helps.

Do not prepare new versions of the documents.

You are advised to work through the documents in the order in which they are listed.

If you have questions about this assignment, send them to J.B.Wordsworth@ex.ac.uk. Questions, and my responses to them, will be published on a Web Page accessible from http://www.dcs.ex.ac.uk/~jbwordsw/InfoSysDes/j4isd.html.

Prepared on 25 October 2004.
Updated on 28 February 2005.