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Chap.7, p.1
IM 341
Business Systems Analysis
Chapter 7 - Notes
Selecting the Best Alternative Design Strategy
I. Selecting the Best Alternative Design Strategy - Two steps:
1. Generate as Comprehensive set of alternative design strategies (what is
Comprehensive? How can we accommodate ALL possible alternatives?);
2. Select the one most likely to result in the desired information system
given all the organizational/economic/technical constraints (Just what is “the
desired information system”? Desired by whom? Which requirements are filled
and which unfilled?)
Design Strategy – a particular approach to developing the system
A. The Process of Selecting the Best Alternative Design Strategy:
1. Divide requirements into different system capabilities from bare
minimum to most elaborate/advanced; or, alternatively, represent different
positions/requirements of different, conflicting parts of the organization;
2. List the different potential implementation environments
(hardware, software, networks) that could be used to deliver different sets of
capabilities (choices here may limit development options in the future! It’s
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Chap.7, p.2
NEVER a good idea to choose physical models first because that limits the
system’s capabilities fro the start!)
3. Propose different ways to source/acquire the various sets of
capabilities for the different implementation environments.
Analysts and Management (Steering Committee) may disagree on what is “Best” –
get used to it! The project may very well be stopped altogether at this point due to
considerations of costs/risks vs. benefits, changing organizational needs, changing
priorities of other projects, or resource constraints.
B. Deliverables and Outcomes
1. At least three substantively different system design strategies for
building the information system;
2. A design strategy judged most likely to lead to the most desirable
information system;
3. A Baseline Project Plan for turning the most likely design strategy
into a working information system.
Ok, GET REAL!!!!! In most cases it is tough enough to generate one acceptable,
comprehensive plan that covers all needs/requirements and is within
organizational constraints. Three really good alternatives? GOOD LUCK!!!!!
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Chap.7, p.3
Many organizations do not have the time/funding/(enter your own favorite
constraint) to allow generation of multiple alternatives. Most of the time it is the
job of the analysts to come up with the optimal solution at the first attempt, and it
better be the right one!
II. Generating Alternative Design Strategies – many analysts can see the best
solution as an obvious choice, but this reflects experience in the field and with the
organization. The reason for suggesting three possible solutions is to advance
low/medium/high dollar costs to give the steering committee a choice. However,
all must consider:
1. Minimum system requirements and mandatory features, such as 1. Data
kept in files; 2. System outputs; 3. Analyses to generate the information in the
system outputs; and Expectations of accessibility, response time, or turnaround
time for system functions.
2. Constraints on system development such as 1. a Date when the new
system is required; 2. available financial and human resources; 3. Elements of the
current systems that cannot be changed; 4. Importance/Dynamics of the problem
that may limit how the system can be acquired.
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Chap.7, p.4
III. Issues to Consider in Generating Alternatives – usually revolve around
importance of various system features.
A. Outsourcing – turning over responsibility for some or all of an
organization’s information systems applications and operations to an outside firm.
Outsourcing is a viable alternative that should be considered. Outsourcing issues:
1. Cost effectiveness – a firm specializing in payroll may do the job more
effectively/efficiently than you can do it yourself
2. Overcome operating problems – if a unionized group of employees is too
troublesome, a firm may eliminate the department and outsource the work
3. Core mission – a firm’s core competencies may not revolve around
information systems and management may wish to have another firm take
responsibility for those operations
B. Sources of Software
1. Hardware Manufacturers – produce software that works with their
hardware
2. Packaged Software Producers – if a particular software package
suits your needs, or can be modified to do so, why do it yourself?
3. Custom Software Producers – some firms specialize in producing
software to solve your particular need
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Chap.7, p.5
4. Enterprise Solutions Software/Enterprise Resource Planning
(ERP) – a series of integrated modules which focus on specific Business Functions
(accounting, manufacturing, etc.) rather than traditional functional areas. The idea
is to integrate all parts of a business process (regardless of its place in a functional
area) into a unified information system. Traditional approaches would use
different systems for each functional area. These can work very well, but are
extremely complex.
5. In-House Development - do it yourself, but do you have the time,
finances, or talent available?
C. Choosing Off-the-Shelf Software – must consider Costs, Functionality,
Vendor (support and viability), Flexibility (for you to customize), Documentation,
Response time, Ease of Installation, Ease of Use,
Validating Purchased Software Information – better check it out
WELL before you buy!
D. Hardware and System Software Issues
1. Advantages to running the new system on your current hardware:
a. Lower costs in not purchasing new hardware;
b. Your staff is familiar with the current/existing platform,
operations and maintenance;
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Chap.7, p.6
c. If it runs on the current system, it will probably interface
more easily with existing systems
d. No costs in converting from the old system to a new one.
2. Advantages to acquiring new system hardware:
a. The new software may not run on the old system;
b. Developing a new platform givers the organization the
opportunity to upgrade or expand its current technologies;
c. New platform requirements may allow the organization to
change its computer operations radically (e.g., from mainframe to client-server).
E. Implementation Issues – implementing new systems often require new
ways of performing the same work, new skills/training (EXPENSIVE!), or
disruptions of work while making the transition between systems.
IV. Developing Design Strategies for Hoosier Burger’s New Inventory Control
System
V. Selecting the most Likely Alternative (Hoosier Burger)
VI. Updating the Baseline Project Plan (Hoosier Burger)
Before and After Baseline Project Plans for Hoosier Burger
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Chap.7, p.7
VII. Electronic Commerce Application: Selecting the Best Alternative Design
Strategy (Pine Valley Furniture)
Selecting the Best Alternative Design Strategy for Pine Valley Furniture’s
WebStore