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