Review Questions
8.What are the three major components/tasks of the systems design phase of the SDLC?
The elements that must be designed when building an information system include the following:
1.Human–computer interface
2.Databases and files
3.Processing and logic
9.What are the four options for system conversion? How do they differ from each other?
1.Parallel—Old and new systems are used at the same time.
2.Direct—Old system is discontinued on one day, and the new is used on the next.
3.Phased—Parts of the new system are implemented over time.
4.Pilot (single allocation)—Entire system is used in one location.
10.Compare and contrast the four types of systems maintenance.
1.Corrective maintenance—Making changes to an information system to repair flaws in the design, coding, or implementation
2.Adaptive maintenance—Making changes to an information system to evolve its functionality, to accommodate changing business needs, or to migrate it to a different operating environment
3.Perfective maintenance—Making enhancements to improve processing performance or interface usability, or adding desired but not necessarily required system features (in other words, “bells and whistles”)
4.Preventive maintenance—Making changes to a system to reduce the chance of future system failure
11.What are the advantages and disadvantages of prototyping?
Improved communication is just one of many benefits that can be realized when prototyping in the systems analysis phase. Here are some others:
•Provides a formal specification embodied in an operating replica.
•Greater level of user satisfaction with systems development.
•Delivery of early proof-of-concept.
•Prototype may be easily changed and even discarded.
•Allows productive work to proceed despite initial uncertainties.
•Demonstrates progress at an early stage of development.
•May provide early training for future users of the system.
•May produce some useful deliverables even if the project runs out of time or money.
•Should result in a product that is a better fit for the customer's requirements.
Even though the benefits of prototyping are strong there are disadvantages and potential risks associated with it. The primary concerns are that of excessive change requests and "feature creep". Just by the nature of the iterative process users will again and again request changes. As they reexamine the prototype they may think of new features they would like that are beyond the scope of the original project. These can be controlled with proper planning but both are legitimate concerns. Other concerns include:
•Can result in unrealistic schedule and budget expectations.
•Iterative nature makes it difficult for management to plan and schedule.
•Working prototypes may lead management and customers to believe that the final product is almost ready for delivery.
•People can begin to think of the prototype as the solution.
•The excellent (or disappointing) performance characteristics of prototypes may mislead the customer.
•Prototypes generally lack security, auditing, and other controls, and data integrity may be difficult to ensure.
•Often inefficient and difficult to maintain.
•Tendency not to document.
12.Define outsourcing and list three general types of outsourcing relationships.
Outsourcing is the moving of routine jobs and/or tasks to people in another firm to reduce costs. At least three different types of outsourcing relationships can be identified:
1. Basic relationship
2. Preferred relationship
3. Strategic relationship
or functional ties, to streamline IS operations as needed.
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