12.1
Frameworks for comparing ISD methodologies
Semester 2, 2005
IMS3230 - Information Systems Development Practices
12.2
References
Prescribed text:
Avison, D.E. & Fitzgerald, G. (2003). Information Systems Development: Methodologies, Techniques and Tools. (3rd ed), McGraw-Hill, London.
Chapters 25, 26, 27
12.3
Frame works for comparing and evaluating ISDMs
paradigms
frameworks
comparing methodologies
selecting a methodology
12.4
paradigm:
“the most fundamental set of assumptions adopted by a professional community that allows its members to share similar perceptions and engage in commonly shared practices”
Klein and Hirschheim (1989)
ontology:
assumptions about the nature of the physical and social world
epistemology:
assumptions about knowledge and how to acquire it
Frame works for comparing and evaluating ISDMs
12.5
Science vs systems paradigmsThe science paradigm: embodies scientific method
reductionism, repeatability, refutation reduce the complexity and variety of the real world, analysis
and synthesis strategies, cause and effect relationships knowledge is validated by the repetition of experiments
producing the same results knowledge is built up by hypotheses being refuted suited to the world of natural phenomena
Wood-Harper and Fitzgerald (1982):
E.g. traditional approaches, data analysis, structured approaches
12.6
the systems paradigm: embodies a holistic approach holistic: emergent properties properties of systems: purpose, interaction of
elements, openness, communication and control understand system context multiple viewpoints suited to the social world
Wood-Harper and Fitzgerald (1982):
E.g. human activity system approaches (e.g.SSM), participative approaches (e.g. ETHICS)
Science vs systems paradigms
12.7
Objectivist and subjectivist paradigms
Klein and Hirschheim (1989)
the objectivist paradigm a realist ontology:
reality is objectively given, exists independently of our perceptions of it
there is one “correct” view which is discoverable a positivist epistemology:
explain observable phenomena by identifying causal relationships
same methods are appropriate for the natural and the social worlds
12.8
Klein and Hirschheim (1989)
the subjectivist paradigm a nominalist ontology:
reality is subjectively constructed via our framework of values, beliefs and experiences
there are different, valid viewpoints an interpretivist epistemology:
relativistic, questions the existence of “objective” knowledge
we need to understand the way in which the world is interpreted
Objectivist and subjectivist paradigms
12.9
implications for systems development methodologies:
system developers must conduct enquiry system developers must intervene in the organisational
social world
objectives of systems development techniques and tools role of systems developers
Objectivist and subjectivist paradigms
12.10
Frameworks
for describing the concept of a methodology
e.g. the meta-model of Olle et al (1991)
for describing a specific methodology
e.g. the system lifecycle
for comparing and / or evaluating methodologies
e.g. feature analyses
analyses of results of using methodologies
12.11
Frameworks for comparing feature analyses:
identify a set of desirable features
determine whether specific methodologies have each feature
attempt to evaluate to what extent features are present problems with feature analyses:
- determining the features
- versions of methodologies
- problems of terminology
- subjectivity of analysis
- subjectivity of evaluation
12.12
a generalised framework of features for comparison:
Avison and Fitzgerald (1995) Chap 7 features:
- philosophy
- model
- techniques and tools
- scope
- outputs
- practice
- product
There are other important features: e.g.
Frameworks for comparing
12.13
Selecting an ISD methodology contingency approaches: there is no best methodology
selection depends on the project context:
- the nature of the problems being addressed
- the nature of the applications
- the nature of the organisation and its culture
E.g. Burns and Dennis (1985): project uncertainty (high / low) project complexity (high / low)
e.g. ill-structuredness of problem situation, system size,
the user component, the developer component
the state of flux of the system requirements
12.14
NIMSAD (Jayaratna 1994): evaluate using three criteria
problem situation (context): how does the methodology help understand the problem
situation?
problem solver (methodology user): what are the values, skills, experiences etc. of the user? how do the users’ values relate to those of the methodology?
problem solving process (methodology): how does the methodology assist in defining, documenting
problems and designing solutions?NIMSAD has been applied to SSM, ETHICS, and Structured Analysis
Selecting an ISD methodology
12.15
a wide range of system development methodologies exists no single system development methodology will suit all
projects and organisations
solutions to this problem: construct a tool kit of methods, techniques and tools to
select from build a blended methodology (e.g. Multiview) build a methodology in-house tailored to the needs of the
organisation
Adopting an ISD methodology
12.16
The tool kit approach
models used within different systems development methodologies are tools available to the analyst
select according to the needs of the situation
disadvantages no integrating philosophy: just a set of methods, tools and
techniques idiosyncratic, unmaintainable systems selection of appropriate techniques etc. requires skill and
experience difficulty in training new systems analysts lack of standardisation
12.17
Build a blended methodology
“blend” the best of existing approaches:
(e.g. Multiview)
difficulty of merging incompatible philosophies difficulty of integrating outputs produced using one
approach with those of another approach analysts need to understand and be experienced in
using several different approaches
12.18
Tailored, in-house methodology
develop a “tailored” methodology based on an existing approach:
underlying philosophy provides rationale for products and processes
techniques and tools are integrated
customised to fit in with the organisational environment
12.19
the need for an ISD methodology
a “better” end product:
acceptable? available? maintainable? meets requirements? etc......
a “better” development process:
project control? productivity? fewer resources used? a standardised process:
a common organisational approach?
or flexibility? creativity? how are systems development methodologies really selected?
Adopting an ISD methodology