Assignment Questions -

Question 1: Read the scenario in Appendix 1 (Pickerings Properties).

(a) List the functions of the system, as perceived by an external user.

(b) List the external entities. Note that because we are modelling the data flows, not use cases, the external entities should be the actual sources and sinks of data rather than the persons keying in the data.

(c) Produce a context (or level 0) data flow diagram using the method described in the unit materials.

Question 2: Based on your work in question 1, and the scenario in Appendix 1, draw up data flow diagrams to capture the proposed system. Use the method described in the unit materials. You should submit:

• A full system (or level 1) diagram.
• A level 2 diagram for the process that arranges a visit.

Question 3: Read the scenario in Appendix 1 (Pickerings Properties) and draw up an entity relationship diagram to show the relational data model for the proposed system. Use the method and notation described in the unit materials.

Question 4: The documentation for an existing module contains the following Jackson Structured Programming diagram,

The actions and conditions list has been mislaid, but fortunately the designer has also shown all the actions and conditions in the diagram

You are asked to produce

(a) A report on how the diagram should be interpreted for a programmer colleague who does not understand JSP. The report should explain the concepts and conventions of the methodology including an explanation of the symbols used in the diagram.

(b) A representation of the program design using structured English. We do not insist on any particular pseudocode conventions but your representation should be highly structured and include appropriate indentation.

Question 5: This question is based on the requirements of a system to record band bookings at gigs. (A 'gig' is an event at which one or more bands are booked to play). You do not need to know about the full system and you should base your answer to this question on the following extract of the design.

Part of the design of the static data is represented by the following entity relationship diagram.

When a booking is made for a gig, the band and the gig need to be identified, and input provided for the length of the spot, and whether the band uses its own sound system. Where the band uses its own sound system the Tech_Phone value should be printed to the screen.

Based on the above scenario:

(a) Draw a dialog structure diagram.

(b) Draw a wire frame (or series of wire frames) based on the structure diagram.            

(c) Drawing on what you have learned in this unit about design principles, write a brief justification (approx 300 words) of your design.

Appendix 1

Pickerings Properties

Pickerings are a firm of real estate agents. They operate as explained below and need to store the data described. Note that though this scenario is based on a typical real world situation it is simplified to restrict the amount of routine work needed to produce the assignment outputs.

When a seller approaches the agency, a simple survey is undertaken by one of the partners (this is unofficial and just for the information of the agency) and then a sale price is agreed with the seller. The partner who undertakes the survey is recorded as the person with overall responsibility for the property. The property is then entered in the properties register, and is available to be included in brochures and invitations to view. When a property is registered it is given an area code. Each area code is associated with relevant information (here restricted to a postcode area - for example NE39 - the name of the area, and a description of the area). The property is also given a category symbol, which corresponds to general descriptions of properties, for example terraced, 2 bed semi-detached, 3 bed semidetached, bungalow etc. There should be scope for existing categories to be given more detailed descriptions in future.

When a customer makes a general enquiry, they are asked to specify a type of property and an area. (Though in practice they might specify multiple types and areas, for this prototype you are asked to provide only for enquiries with one area and type). A custom-made brochure is produced showing suitable properties in the required area. From time to time block mailings are done of newsletters that are similarly customised on the basis of customer preferences.

When a customer asks to see a particular property a visit is arranged. A visit must always involve a partner, but it need not be the one with overall responsibility for the property. A record is made of all visits that take place, including details of the partner and enquirer making the visit, and a brief comment on the outcome.

If an offer is made for a property this agency does not allow further visits to be arranged until the owner has had time to respond to the offer made. (Where visits have already been made, the enquirer is informed that the property is under offer and the appointment cancelled.)

At weekly intervals a report is made to the managing partner of new properties taken on, visits made and offers achieved, during the preceding week.