System Analysis And Design

DIPLOMA IN COMPUTER SCIENCE. TEST PAPER Instructions: Answer any FIVE questions in this exam. All questions carry equal marks. Time: 3 Hours 1. (a) State four differences between impact and non-impact printers. (2 marks) (b) In its corporate strategy, an organization has decided to phase out its traditional file system in favor of a database system. Outline four benefits that this organization is likely to achieve out of this move. (4 marks) (c) Distinguish between logical and physical database design. (2 marks) (d) Table 1 shows data from ALR Limited purchasing department. Order No 123

OrderDate CustomerNo CustomerName ItemNo

ItemQuantity ItemPrice

11/12/98

1001

Tom

A12

19

240

126

11/12/98

1002

Jane

A11

2

60

127

12/12/98

1001

Tom

A14

2

145

Table 1 Using Table 1, normalize the data to 3rd normal form clearly showing all the tables. marks)

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2. (a) Systems analysts require interpersonal as well as technical skills, although the necessity for both skills depends on the stages of system development. Illustrate on a sketch the level the level of the two skills expected across the phases of system development (Analysis, Design, Implementation, and Maintenance). (5 marks) (b) During system development, a designer received a requirements specification document. i. Identify the document that will be produced in the next stage of the system development. ii. Describe six items to be included in the document identified in b (i) (7 marks) (c) Suppose that Kshs 300,000 is to be invested in a vehicle tracking system and the average annual benefit is Kshs 150,000 for the four year life of the system.

i. ii.

Determine the Net Present Value (NPV) as a percentage of the investment at a discounted interest of 10% Evaluate the viability of the system. (8 marks)

3. (a) State two disadvantages of using SSADM over the waterfall approach. (2 marks) (b) Explain four qualities of a good system. (4 marks) (c) Distinguish between hard and soft system thinking. (4 marks) (d) A car manufacturing company sells a wide range of cars to either “resellers” or “individuals”. All orders from resellers are charged at normal price less 50%. Individuals are defined as either “financed” or “self”. Financed individuals are charged at normal price less 20%. Self individuals are charged at normal price less 40% for cars with engine capacities greater than 3,000 cc, normal price less 20% for engine capacities of 1,500 cc to 3,000 cc and normal price for engine capacities of less than 1,500 cc. orders are processed in batches, each batch commencing with a header record and terminating with a trailer record. i. Construct a decision tree for the procedure used by the company. ii. Assess the suitability of the decision tree drawn in d (i). (10 marks) 4. (a) During the design and development of a computerized information system, various types of documentation are produced. i. Explain five functions performed by these documentation. ii. Describe five items to be included in program documentation. (10 marks) (b) A company which serves all its customers from one central warehouse has decided to computerize its operations. It has also decided to close the central ware house and establish five regional warehouses, each of which will be linked to a central mainframe computer. The mainframe computer will have on-line links to regional warehouses where data entry of customer orders and stock replenishment will take place. You have the responsibility of planning for the implementation of the system i. State the most appropriate changeover approach justifying your answer. ii. Identify the issues which would be considered during the implementation. (10 marks) 5. (a) Interviews are sometimes unsuccessful because of poor interviewing techniques or lack of preparation on the part of the interviewer. Prepare a checklist of six guidelines which can be used by a systems analyst to conduct a series of interviews with user department representatives. (6 marks)

(b) A large mail order firm operates through several thousand local agents, whose customers are mainly friends and relatives. An agent receives a new catalogue quarterly. Customers select goods from the current catalogue and then pay the agent the appropriate amount, receiving in return a receipt detailing goods ordered and moneys paid. The agent adds their orders to an order form and pays their money into a separate account used solely for business. Every Saturday the agent posts the order form (now containing items ordered by a number of people), together with a single cheque drawn on the business account, retaining a copy of the order form, which is kept in a red binder. The company sends items ordered by post together with a delivery note. The agent checks the items received against both the delivery note and his/her own copy of the order, using telephone calls to resolve any discrepancies. If all is satisfactory, the agent then throws away the order form but retains the delivery note in a blue binder. At the end of every quarter the agent receives along with the new season’s catalogue, a statement of all items ordered in the quarter, together with commission cheque for 10% of their total value. After checking the details against the delivery notes in the blue binder, the agent deposits the commission into his/her personal bank account. Draw a data flow diagram depicting the above procedure. (14 marks) 6. (a) As a Systems analyst, you are required to give a representation to the organization which has contracted you to improve their existing computer system. i. Create an agenda for your proposal presentation to the senior management of the organization. ii. List three possible visual aids that you would use during the presentation.(8 marks) (b) Describe the type of screen dialogue that is most suitable for the following personnel. i. A senior manager consulting a system infrequently to obtain summarized information. ii. An experienced programmer. (6 marks) (c) Describe three file organization methods. (6 marks) 7. (a) Testing a system is very important in system development i. Explain the purpose of testing ii. Describe the testing process that a system would undergo until it is fully operational. (8 marks) (b) A batch processing sales accounting system has been operating successfully for a number of years. However, records rejected by the validation programs within the system have increased from 4% to 15% over the past six months, and computer operations staffs are finding it increasingly difficult to run the system within its established operating schedule. i. Identify the likely contents of statement of requirements

ii.

State five items that would be expected to be included in the suppliers’ proposal for evaluation of the best candidate system. (12 marks)

8. (a) Describe five requirements of forms design. (5 marks) (b) The Nakata supermarket chain has a number of regional warehouses which supply all its supermarkets in that region. All supermarkets’ orders are placed with the appropriate regional warehouse for any stock requirements. The regional warehouses then break down the supermarket purchase orders, which can contain many types of products, into bulk order lines as well as being validated against the master products file. Bulk purchase orders are created from order lines and sent to appropriate bulk product suppliers. NOTE: Most bulk product suppliers have a range of different products. Deliveries received from bulk suppliers always relate to an entire bulk purchase order. A purchase order will relate to only one delivery. All bulk product suppliers provide product catalogues from time-to-time giving details of all the products they supply as well as addresses, telephone and fax numbers. Create an Entity Relationship Model for the Nakata System. marks)

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