INFORMATION SYSTEMS @ X
Finalizing Scope (functions/level of
automation)
 Finalizing scope in terms of functions and level of
automation for each function overlaps with and
requires information from:


Defining target deployment environment
Defining implementation alternatives
> e.g., build vs. buy
 General Approach for including/excluding functions:
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Functions deemed mandatory are in scope.
Include as many important functions as budget and schedule allow
Desirable features: delay to later ‘release’ of system
 Strategic plan:


Often, genesis of a new system is organization’s strategic plan
Functions that align with strategic plan typically get included in scope
INFO425: Systems Design
INFORMATION SYSTEMS @ X
Finalizing Scope (functions/level of
automation)
 Need to revisit feasibility analysis. Now have much more
information to work with.
 Economic feasibility


What set of functions give us an optimal return on investment?
What set of functions can we afford?
 Schedule and resource feasibility

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What can be implemented in time available?
What can be implemented given human and other resources?
Technological feasibility

What can be practically implemented given state of technology and
organizations knowledge and experience?
 Operational, organizational, and cultural feasibility


What can our organization handle/accept?
How much change is required?
INFO425: Systems Design
INFORMATION SYSTEMS @ X
Application Deployment Environment
 What is the technical environment in which system will be
implemented?
 Deployment environment consists primarily of:





Hardware
Networks
System software
Development software
Development methodology and tools
 Technical requirements define constraints regarding
deployment environment
 Organization’s current environment/standards typically drive
deployment options
INFO425: Systems Design
INFORMATION SYSTEMS @ X
Range of Application Types
 Stand-alone applications on mini- and personal
computers
 Online interactive applications
 Distributed applications
 Web-based applications
INFO425: Systems Design
INFORMATION SYSTEMS @ X
Hardware, System Software, and Networks
 Computers range from handheld to super
computers
 Operating systems range from Windows to Unix
 Database management systems range from Oracle
to SQL Server to IBM DB2
 Software components and standards range from
Java 2 Enterprise (J2EE) to Microsoft .NET
 Web servers range from IIS to Apache
INFO425: Systems Design
INFORMATION SYSTEMS @ X
Deployment Environment Characteristics to
Consider
 Compatibility with technical requirements:

Volume of transactions, location of users, etc.
 Compatibility among hardware and system
software
 Required interfaces to external systems
 Conformity with IT strategic plan and architecture
plans
 Cost and schedule
INFO425: Systems Design
INFORMATION SYSTEMS @ X
Development Tools
 Development environment – programming
languages, CASE tools, and other software used to
develop application software
 Java and Visual Studio .NET are examples
 Application deployment environment decisions
limit development tool choices

Operating system environment

Database management system (DBMS)

Distributed software standard
INFO425: Systems Design
INFORMATION SYSTEMS @ X
Development and System Software
Environments
 Consists of standards and tools used in an organization to
develop systems
 Important considerations

Language environment and expertise
> Java, C, etc,

Existing CASE tools and methodologies
> RUP and Rose, Information Engineering


Required interfaces to other systems
Operating system environment
> Unix, Linux, OS390, NT

Database management system environment
> Oracle, DB2, SQL Server
INFO425: Systems Design
INFORMATION SYSTEMS @ X
Choosing Implementation Alternatives
 Many variations on obtaining a system




Facilities management solutions
Packaged, turnkey, ERP software systems
Custom software development
In-house development
INFO425: Systems Design
INFORMATION SYSTEMS @ X
Implementation Alternatives
ERP
SAP
PeopleSoft
ASPs
Salesforce.
com
MySAP.com
Off the shelf
packages
Simply
Accounting
We build, consultants build or
blended approach
INFO425: Systems Design
INFORMATION SYSTEMS @ X
Identifying Criteria for Selection
 Comparisons difficult
 Different proposed systems have strengths in different
areas
 Need a consistent framework for comparison of
alternatives



Criteria
Weights
Scores
 Three areas to consider



General requirements
Functional requirements
Technical requirements
INFO425: Systems Design
INFORMATION SYSTEMS @ X
Evaluation Framework
Weight – importance
of criteria vs other
criteria
Alternatives
considered
Evaluation
Criteria
Score
INFO425: Systems Design
Score *
Weight
Total
49
Total
42
INFORMATION SYSTEMS @ X
EVALUATION FRAMEWORK (EXPANDED)
INFO425: Systems Design
INFORMATION SYSTEMS @ X
General Requirements
 General requirements include considerations that
are important but not directly associated with the
computer system itself.
 Related to feasibility assessment – alternative
must be feasible to be chosen
 General requirements examples:









Performance record of the provider
Level of technical support from the provider
Warranties and support services (from outside vendor)
Availability of experienced staff
Development cost
Expected value of benefits
Length of time (schedule) until deployment
Requirements for internal expertise
Organizational impacts (retraining, skill levels)
INFO425: Systems Design
INFORMATION SYSTEMS @ X
Technical Requirements
 Constraints under which system must operate
 Defined by technical requirements identified during
information gathering
 Categories:


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


Performance (response time/throughput, etc)
Security and Control
User interface (ease of use, etc.)
Service (number/location of users to be supported)
Operating environment
etc.
INFO425: Systems Design
INFORMATION SYSTEMS @ X
Functional Requirements
 Need to evaluate alternatives based on how well
they meet functional requirements.
 Use expanded event table
INFO425: Systems Design
INFORMATION SYSTEMS @ X
Evaluating Functional Requirements
INFO425: Systems Design
INFORMATION SYSTEMS @ X
Evaluating Technical Requirements
INFO425: Systems Design
INFORMATION SYSTEMS @ X
Making the Selection


After rating alternatives, choice can be made
Scores are tabulated and compared
INFO425: Systems Design
INFORMATION SYSTEMS @ X
Partial Matrix of General Requirements
Figure 8-7
Systems
Analysis
INFO425:
Systems
Design
and Design in a Changing World, 5th
20
INFORMATION SYSTEMS @ X
Partial Matrix of Functional Requirements
Figure 8-8
Systems
Analysis
INFO425:
Systems
Design
and Design in a Changing World, 5th
21
INFORMATION SYSTEMS @ X
Partial Matrix of Technical Requirements
Figure 8-9
Systems
Analysis
INFO425:
Systems
Design
and Design in a Changing World, 5th
22
INFORMATION SYSTEMS @ X
Contracting with Vendors
 Generate a Request for Proposal
INFO425: Systems Design
INFORMATION SYSTEMS @ X
Presenting Results and Making Decisions
 Compile, organize, and present the alternatives and
critical issues in an easy-to-understand but complete
manner
 Final choice generally made by executive steering
committee
 Format of documentation and presentation style varies
with organization
INFO425: Systems Design