Grace Aasen
CISP 457 Systems Analysis and Design
Tim Wei
Chapter 5 Homework
Dec. 15, 2005
Check It Out: Working with Prototypes and Prototyping
You are an IT consultant, designing a new check-out system for the Phoenix Public
Library System. You decide to create a prototype that librarians can evaluate before the
final design is implemented. In order to explain the process of prototyping to the
librarians, you are asked to write a report that will be distributed to them prior to their
evaluating the prototype. Follow these steps to create a report that will be easily
understood by users:
1. Explain the main purpose of prototyping.
The main purpose of prototyping is to give the users a non-abstract system
design that they can evaluate early in the process to avoid costly redesigns
later.
2. Explain why a prototype might or might not evolve into the final version of the system.
Name the label for each type of prototype, and give an example for each.
If a prototype is developed using system prototyping, the prototype is a
model of the entire system and, if it meets user requirements, can be
fleshed out into a full information system. Rapid Application Development
(RAD) uses iterative system prototyping to create the final application.
A prototype designed using design, or throwaway, prototyping is meant to
be discarded after user review, whether or not its design details will be
incorporated into the final version. This is frequently used to do mock-ups
of user input screens, for example, before the back-end code is developed.
3. Describe the tools typically used in developing prototypes.
CASE tools speed development by automatically creating diagrams and
sometimes even code from analyst input. Combining CASE tools with 4GLs
and application, report, and screen generators gives systems analysts the
ability to create information systems quickly and accurately with effective
documentation.
4. List three advantages and three disadvantages of prototyping.
Advantages:
 Users get to see, and possibly interact with, a system rather than
imagining what it will be like.
 Design problems are identified and corrected earlier in the process.
 TCO can be lowered by early design refinements, or even scrapping a
project when it becomes apparent that it won’t succeed.
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Grace Aasen
CISP 457 Systems Analysis and Design
Tim Wei
Chapter 5 Homework
Dec. 15, 2005
Disadvantages:
 The prototype is not a fully-functioning system, so there may be key
details that are not identified until the system is complete.
 If the prototype is too elaborate, the work put into it can actually delay
the project as a whole.
 Prototypes are generally used to test short-term needs. Long-term
functionality issues may be overlooked.
Configure This!: Considering Software Acquisition Options
You are an IT consultant to a large hardware/software company which prides itself on
selling "solutions" rather than products. A project under consideration is the development
of a "Configurator," an expert system which would take as input a customer's
requirements and produce as output a system composed of hardware and software
produced by the company. The Configurator would "know" all the constraints on the
system, all the possible hardware and software products, and how to put them together.
It would embody the wisdom of the company's best experts in each field. It would be
used by Sales, Marketing, Inventory, Accounting, the Factory, Maintenance, and
perhaps others. Among its outputs would be the information needed by each
department, for example a Bill of Materials and a Factory Design Diagram for the
system. You have been asked to research all of the possible alternatives that the
company has in developing this system. Prepare a report to present to the IT team,
based on the following:
1. Explain alternatives concerning software acquisition.
One way of implementing the Configurator would be to develop the system
in-house. This means that a team internal to the company would be
responsible for planning, designing, and implementing the final product.
This option typically results in a solution that most closely follows the
design requirements and customization. However, it also is generally the
most expensive and most time-consuming option.
Another option is to buy an off-the-shelf software that is already functional
and merely requires installation and setting the options. This is a relatively
inexpensive option, although it may not match the company’s needs
exactly.
A third option is a combination of the two where the company purchases
off-the-shelf software that can be customized to meet specific
requirements. This results in a compromise between cost, effort, and
customizability.
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Grace Aasen
CISP 457 Systems Analysis and Design
Tim Wei
Chapter 5 Homework
Dec. 15, 2005
2. Describe software outsourcing options, including offshore outsourcing and the role of
service providers.
Some software is now being offered as a service, rather than a package. An
example of this is MyFamily.com, which hosts websites in which family
members can post message, chat, share pictures, and create family trees.
There is no software that is purchased; rather, a fee is paid to access the
capabilities of this website. Companies that provide these services are
called Application Service Providers (ASPs) and they provide a wide variety
of services.
Another outsourcing option would be to hire employees or companies that
are outside the United States to do the system development. This is an
attractive option to many companies because of the lower cost of overseas
labor. However, there are other complexities that come with offshore
outsourcing that can offset the financial gains.
3. Explain the advantages and disadvantages of developing software in-house versus
other alternatives.
See #1.
4. Using the information in your report, and something of your imagination, make a
recommendation to the IT team as to what should be done about the configurator.
It is my recommendation that the Configurator be developed in-house. Any
software we could purchase to create the Configurator would be, in fact,
competition for it. Therefore, the company’s eventual business success
lies in the superiority of the product. In-house development would increase
the quality of the Configurator because it would be developed to the
company’s exact specifications. Also, in-house staff would have the best
access to the intellectual assets present in the company, the factor that will
make the Configurator stand out in the crowd of similar products.
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