1. In what way(s) is a decision tree and a data flow diagram related? What about a decision tree and structured English? (5)

A DFD is a pictorial model of systems analysis whereas a decision tree is a method to describe a process appearing in a DFD. Decision trees and Structured English are both methods to describe a process appearing in a DFD.

 

2. Prototyping is not a panacea for system development. Explain. (5)

Prototyping has weaknesses too. These include inadequate analysis, inefficient systems since they are driven by user needs, longer response time for the system and for resolution of open issues between the developers and users, and private data / programs.

 

3. Draw a decision table for the following policy for charging for certain in-flight services in charter flights: "If the flight is more than half full and costs more than $350 per seat, we serve free cocktails unless it is a domestic flight. We charge for cocktails on all domestic flights ... that is, all the ones where we serve cocktails (cocktails are served on all flights, domestic or not, that are more than half-full)." (5)

<Diagram to be filled in> 

 

4. What advantages does a data dictionary offer in the area of documentation? (5)

A nation-wide manufacturer of convenience foods distributes its products by truck to grocery stores, supermarkets, and convenience stores throughout the country. Over 5,000 drivers fan out from 100 distribution centers across the nation each day, delivering over 100 different products to customers. There is considerable variety in the size of customer operations and in the sale of products. In some stores one type of product may sell well and another may sell only very slowly. A different location may have just the opposite results. Since the products have a limited shelf life, freshness is an important consideration from the beginning of the manufacturing process to delivery to the store shelves. Thus, it is important for sales information to be accurately and quickly transmitted from the supermarket to the manufacturing facilities. Mistakes or delays show up in lost sales and in improper production levels. Also, losses sometimes occur because of over- production. Because of the large number of products, the order form used by the company is long and complicated. The form's complexity only adds to the possibility of mistakes and is thus disliked by drivers and store managers alike. The paperwork is excessive at the company's headquarters. When order forms reach the headquarters, order details are keyed into the company's large computer system. Nearly 1000 data entry operators are employed just to perform this work, since the information they enter is important for planning and scheduling of manufacturing and for determining what each customer is selling.

Another approach has been proposed. Several corporate managers and a senior systems analyst have been meeting to discuss the idea of replacing the widely used paper order form with hand-held computers. Under the new system, the 5000 route drivers would each be given a hand-held computer and a computerized printer would be installed in each truck. The driver, who is actually a route salesperson, would take the computer into the store and enter the details of what items and quantities are needed to restock the shelves of the particular customer. Back at the truck, the order information would be printed out on the spot and the items could be removed from the truck and placed on the customer's shelves. The ordering information from each of the fifty or so stops each driver makes during a single day would be retained in the memory of the hand-held computer throughout the day. The identity of each customer would also be retained. At the end of the day, the driver would connect the hand-held computer to a communications line, transmitting the day's business to the headquarters for processing.

• The team of analysts wishes to evaluate this application of developing a prototype of the system. Using the information provided above (and remembering that the application focuses on order entry, common to businesses of all types), explain what benefits you believe will accrue from using the prototyping development method. (5)

1. Most important, determining system requirements.
2. Second, validating systems design.

• Describe the features you believe should be included in a prototype of this system. Explain your rationale. (5)

1. User friendly menus for data entry
2. Automated error checking
3. Inventory updating
4. Robustness and hardiness of the machines
5. Communications set-up and software to test feasibility.

• What information do you need to begin the prototyping effort? (5)

1. User reactions
2. Contents of the order entry system
3. Data updation and integrity check methods
4. Availability of funding and manpower

• Who should participate in the prototyping effort? Why? (5)

1. Drivers as principal users
2. Corporate managers interested in planning
3. Finance managers for funding and control