Title: SocioTechnical Perspectives on Methodologies '
1Socio-Technical Perspectives on Methodologies .
- Look ahead to rest of module
- Trends in hard methods
- Examples of softer methods
- Pressures for new approaches to ISD
- Methods are contentious
- Slogans
2Trends in hard methods
- Trends in hard methods
- Early approaches
- Structured approaches
- Data-driven approaches
- Object-Oriented approaches
Trend is towards compatibility with, or
accommodation of, softer approaches
3Trends in hard methods
- Early years
- 1940s scientific problem solving computers were
tools for the scientists that built them no
need for any method to support development. - 1950s early business data processing, grew
rapidly in 1960s. Problems included - Carry over of culture from 1940s, but developers
were less expert and not as continually engaged
in programs they developed the need for clearly
written, understandable programs rather than
obscure, complex programs emerged. - Need for some broad principles of programming and
higher level programming languages. The latter
made feasible by improvements in storage
technology. - No formal training of ISDers. Need for academic
courses. - By early 1960s programming problems dominated ISD
and the phrase software crisis was coined.
(Budgets, deadlines exceeded, no workable
outcomes of projects).
4Trends in hard methods
- Early Systems Analysis methods
- Early focus on software crisis soon developed
into realisation that systems analysis and design
phases of ISD were also of critical importance. - Early methods were lifted from industrial
engineering and used modified flow charts. - More advanced methods were developed by e.g. NCR
and IBM. These included ideas like - separating Analysis and Design phases completely
from programming - defining required information outputs first then
working out what minimum data input was required.
From this the requirements for a database could
be worked out. - Defining overall organisational information needs
5Trends in hard methods
- The Systems Development Life-Cycle
- Idea of a systematic, reductionist approach
evolved though 1960s into the waterfall SDLC
(Royce,1970) - Stage-limited commitment
- Discrete stages
- Signoff of interim end-products
Planning
Analysis
Design
Implementation
6Trends in hard methods
- The Structured Approach
- Developed out of waterfall life-cycle
- probably the most widely-known and widely-used
approach. - this top-down approach evolved bottom-up from
structured programming. - structured programming.
- Programmers should be constrained to 3
constructs - sequence, selection, iteration
- Unrestricted branching should not be allowed
- GOTO
7Trends in hard methods
- The Structured Approach
- structured design
- Cleaning up programming with structured
programming didnt solve the software crisis, it
just revealed pollution upstream. - Top-down, functional decomposition into modules.
- Cohesion and coupling of modules
- Maximise (internal) cohesion
- Minimise (minimise) coupling
- Information hiding by modules (need to know
analogy)
8Trends in hard methods
- The Structured Approach
- structured analysis
- More pollution upstream revealed.
- Data flow diagrams
- Entity relationship diagrams
- Data Dictionary
9Trends in hard methods
- The Structured Approach
- The technical elements could be coupled with
management elements such as - Walk-throughs
- Team reviews
- Sign-offs
- Phased-deliveries
- It could be sold in form of training courses and
books. - It was seen as a silver bullet for a time.
10Trends in hard methods
- The Structured Approach
- Criticisms and weaknesses
- Transition from analysis to design is poorly
defined. - Attempts to solve this by distinct
logical/physical modelling didnt work. - Complete set of structured approaches tend not
to be used - practitioners select what works for
their circumstances. (But approach is not
designed to be used like that). - It disregards problems posed by differing
interests and power. (Bansler and Bodker) - Essentially process-driven, didnt address the
structure of data (it did later). - One of key originators, Ed Yourdon, described it
as irrelevant and obsolete given modern
development environment.
11Trends in hard methods
- The Structured Approach
- Legacy
- Modules
- Interior of modules clearer and more maintainable
- Exterior of modules clearer and more maintainable
- Large programs composed of modules more
comprehensible. - Design more visible due to graphical
representation of system structure.
12Trends in hard methods
- Data Driven approach
- Couldnt really emerge until disk-storage had
developed - Data structures seen as more stable than
processes - Evidence showed that good solutions often used
processing structures that mirrored data
structures. - Recognition that data (information, knowledge) is
an important organisational resource and should
be managed accordingly. - Example SSADM despite its name
- Data-driven but incorporates
- Structured programming
- Event modelling
13Trends in hard methods
- Object-Oriented Approach
- Object-orientated approach dates back to at least
1960s (Simula programming language). - Process and data are encapsulated in a single
entity. - Advantages of O-O approach
- Maps to real world objects well
- Natural modelling technique (UML)
- Single representation used throughout life cycle
- Facilitates re-use.
- Claimed to facilitate communication between users
and developers. - Examples of current methodologies
- Rational Unified Process (www.rational.com)
- Unified Software Development Process (see Bennett
et al.) - Extent of take-up in business domain is unclear.
14Examples of softer methods
- Examples of softer methods
- Participative approach
- ETHICS
- DSDM
- SSM
15Examples of softer methods
- Participative Approach
- See first lecture Scandinavian Approach
16Examples of softer methods
Effective Technical and Human Implementation of
Computer-based Systems. (ETHICS) is a
technique and also a philosophy that future users
of new technical systems should be able to
participate in the design process and help create
systems that are humanistic and friendly as well
as efficient and effective (Enid Mumford, Comm.
Of ACM, July 1993, p.82)
- Arguments for participation
- Ethics. People have a basic right to control
their own destinies, and this applies in the work
situation as elsewhere. - Expediency If people do not have a say in the
decisions of others, they may repeal or subvert
the decisions as soon as those others leave the
scene. - Expert Knowledge People who are the experts on
topics such as task design are the people who do
the jobs. - Motivating Force Participation is a motivator and
will increase the productivity and efficiency of
the eventual system.
17Examples of softer methods.
ETHICS
- Socio-Technical Satisfaction
- knowledge fit
- knowledge being developed to make staff
increasingly competent - psychological fit
- job matches employees status, advancement and
work interest - efficiency fit
- effort-reward bargain
- work controls matching employees expectations
- supervisory controls
- task-structure fit
- degree to which tasks are demanding or fulfilling
- ethical fit
- match between employee values and organisational
values
18Examples of softer methods
ETHICS
- Levels of Participation
- Consultative. Leaves most design decisions to
computer specialists, with system objectives and
the eventual form of the system being greatly
influenced by the users. - Representative. Design group is formed involving
users to design the new work to fit in with the
technology. - Consensus Users are involved continuously
throughout the design process.
19Examples of softer methods
ETHICS
- ETHICS Diagnostic and Design Tools
- A framework to help identify mission, key tasks,
important constraints and factors critical to
effective operation. - A tool to help identify systemic and operational
problem areas. - A framework to help identify what is likely to
change in the internal and external environment. - A set of guidelines for individual and group work
design,
20Examples of softer methods
- Dynamic Systems Development Method (DSDM)
Influences
Participatory Design
Feasibility Business Study
Risk-Driven Development Process (Spiral Model)
Functional Model Iteration
Implementation
Rapid Application Development
Design and Build Iteration
Evolutionary and incremental development
21Examples of softer methods
- Soft Systems Methodology (SSM)
- Involves
- Appreciating the situation
- Representing the situation
- Rich pictures
- Imagining possible relevant systems
- Building models of human activity
- Conceptual models
- Comparison
- of understanding of real situation
- with conceptual models
- Recommendations for change
- Taking action
Influences
Systems Theory
Action Theory (learning from reflection on
practice)
Worldviews, including that of developer
Stakeholder participation
22Pressures for new approaches to ISD
- Pressures for new approaches to ISD
23Pressures for new approaches to ISD
- (Reminder) Information systems are developed for
a specific situation in a specific company at a
specific point in its history. - In todays context
- The software for many IS is not built from
scratch but is tailored from some more
general-purpose package - e.g. Enterprise Resource Planning (ERP) systems
Oracle, SAP - Some ISD deploys off-the-shelf packages
- Configuration development integration of package
software to incorporate local conditions - Yet even when as IS includes off-the-shelf
software, ISD activities are still necessary to
determine requirements and to fit the
technological product with the situation in which
it is used.
24Pressures for new approaches to ISD
- IS are not only conceptually parts of larger
systems, but their technological components often
interact with components of other systems. - Most ISD these days is not green field
development, but takes within an existing
interconnected IS environment with on-going
complex work practices and skill sets. - This systemic aspect leads to a development
process where knowledge about the context becomes
increasingly important.(Fitzgerald et al.) - The success of a new development is now more
obviously judged by - how well it contributes to the larger system of
which it is a part, - Rather than how well it performs in isolation.
25Pressures for new approaches to ISD
- Changing nature of business environment means
short-term needs dominate given faster
metabolism of business these days. - Altered profile of ISD environment leads to
replacement of large-scale monolithic approaches
with approaches based on a good enough and
frequent tangible results philosophy.
26Methods are contentious
27Methods are contentious
- The use of methods for ISD has been the focus of
much research over a long period of time. The
main point of contention has been whether the
methods actually do help in the development
process (Fitzgerald et al.. 2002,. p3) - Those who earn their living by developing
methods, writing about them or researching them
claim that - practitioners dont understand the need and
benefits of using them. - Practitioners claim that
- available methods dont fit the complexity of the
development situation and that researchers dont
understand this.
28References and Further Reading
- Avison, D.E. Fitzgerald, G. (2003) Where now
for development methodologies. Communications of
the ACM, 46, 1. - Bansler, J. Bodker.K (1993) A reappraisal of
structured analysis design in an organisational
context., ACM Transactions on Information
Systems. 11, 2, 165-193. - Bennet, S. et al. (2002) Object-Oriented Systems
Analysis and Design. (2nd Ed). McGraw-Hill Ch. 3,
21 and 22 - Fitzgerald, B, Russo,N.L. and Stolterman (2002)
Information Systems Development Methods in
Action. McGraw-Hill.