12.1 Frameworks for comparing ISD methodologies IMS Information Systems Development Practices

12.2 Frame works for comparing and evaluating ISDMs  paradigms  frameworks  comparing methodologies  selecting a methodology

12.3  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

12.4 Science vs systems paradigms The 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

12.5 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

12.6 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

12.7 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

12.8 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

12.9 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

12.10 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

12.11  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

12.12 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

12.13 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

12.14  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 theorganisation Adopting an ISD methodology

12.15 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

12.16 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

12.17 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

12.18 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

12.19 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