Transcript Web Information System Development

Web Information System
Development
Goals
• Characterize Web-IS as IS with special emphasis
on people, organizations, strategies.
• Illustrate the need of a flexible development
process.
• Argue on the strengths and weaknesses of UML
and the UP. Show what is missing in the UP.
• Introduce WISDM
• Introduce further techniques to complement the
UP
Termilology
• Web-site
– Emphasis on static presentation of information
• Web-application
– Dynamic site, capable of changing its state as
the result of user interaction
• Web-Information System
– Complex, web-based information system
• Web-solution, web-based system
– Used as generic terms
Building web applications
citation by Jim Conallen (1999)
Building a web site is relatively easy, because the barriers
to entry are low and development is largely uncomplicated.
Building a web application, however, is hard work.
Because of the rich content and its importance to the
business, you’ll have to deal with many different
stakeholders, ranging from graphic artists to code warriors
to lawyers. Additionally, you’ll have to architect your
system for continuous change, because a web application
that is stagnant is a web application that is dead. If you are
webifying an existing client/server system, you’ll have to
cope with the challenge of integrating legacy. Finally,
you’ll have to prepare yourself for periods of peak
interaction; a system that fails at the most critical moments
is one that will seriously harm the business.
Role of Information Systems:
citation from Loucopoulos 95, S.4
• Information systems are entering a new phase, moving
beyond the traditional automation of routine organizational
processes and towards the existing of critical tactical and
strategic enterprise processes. Development of such systems
needs to concentrate on organizational aspects , delivering
systems that are closer to the culture of organizations and the
wishes of individuals.
• Consequences: we need to consider
– Changes and their management
– Integration of various views
– Relationship between information system and organizational strategy
and culture
The four Worlds of Information Systems
Subject
world
(Mylopoulos 92, Loucopoulos 95, Abb. 4.1, S. 73)
The four Worlds of Information Systems
• Subject World:
Application domain, e.g. Bank-application, Hospital IS, etc.
• Usage World:
Users, clients, people who interact with the system;
Viewpoint: User, Human-computer interaction,
communication, …
• System World:
The system to be developed: its functionality, qualities, code,…
• Development World:
The development process, the method employed, the project
team, etc.
Is Web-IS development different?
• 10 concepts relevant to Web-IS development
(Baskerville & Pries-Heje 2001)
• Time pressure. Any advantage is short lived and
will be copied quickly, time is of essence
• Vague requirements
• Prototyping
• Release orientation
• Parallel development
Is Web-IS development different?
(2)
•
•
•
•
•
•
Fixed architecture
Coding your way out
Quality is negotiable
Dependence on good people
Need for structure
Note: Database and application-integration issues
remain the same as in classical IS.
Special features of Internet
projects
 Internet time
 Strategic implication
 Emphasis on graphical user interface
 Customer orientation
• Users with unknown background and equipment
• Communication among various stakeholders
• Content is essential, both its structure and essence
• Navigation is a key issue
Towards a Web-IS development
process
• There exist proposals, but no generally agreed
upon process. (discuss why?)
• The UP (Unified Process) is applicable, although
it has shortcomings.
• There exist web-extensions to the UP that address
some of the more technical issues.
• Essential socio-technical aspects are addressed in
the Multiview approach (Avison et al., 1998) and
WISDM (Web IS Developent Methodology,
Vidgen et al. 2002)
Requirements on a IS development
process
• General requirements on a process model:
– It controls the activities of a team and their
timely order.
– Specifies the artefacts to be produced.
– Offers criteria for the evaluiation of the
activities and products of a project.
Requirements on a Web-IS
development process
• Specific requirements on a Web-IS development
process:
– Iterative, incremental, flexible
– Socio-technical direction: Consideration of
technical, organizational, personal perspective
– Addressing of eContent, graphical, interactional
and and navigational issues
Our strategy to Web IS
development
• Use the UP as powerful generic framework that
can be flexibly taylored and extended by special
techniques to suit the particular project.
• Introduce WISDM to
– offer a methodology for the socio-technical view;
– illustrate a socio-technical framework.
• Introduce various techniques to complement UP
activities in order to better address the specific
features of Web-IS such as
– User-orientation, broad view on requirements, specific
architectural patterns, graphic design, navigation, etc.
6 UP Best Practices that particularly
apply to web-based systems
•
•
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•
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Develop iteratively
Manage and trace requirements
Utilize component architectures
Model visually
Verify quality
Control changes
… Discuss, why these best practices are essential
for web applications
WUP (Web Unified Process)
• Due to the absence of an agreed upon model for
developing web-applications, we introduce our own
process framework
• Goals:
– Build flexibly upon best practices incorporated in the UP
– Provide multiple techniques for requirement engineering
in the requirements workflow
– Consider socio-technical view throughout the process
– Consider views for graphic layout, structure, eContent,
navigation.
WUP – Topic structure
• Review of the UP
• Various requirements engineering techniques to
complement use-case technology
• Socio-technical view and respective
techniques/approaches/hints/mindsettings,
WISDM methodology as Multiview approach
• Special architectural patterns for web applications
• Special issues/views of web applications: eContent,
graphic layout (look and feel), site structure,
navigation.
• Interfacing to databases
WUP – Complementing the UP
For each phase:
Inputs for each phase and iteration of the UP
UP–activities
Web–specific activities
Web-specific activities are discussed in the following chapters
WUP – Initial tasks
• Discuss the topic of your web application and
corresponding visions with stakeholders.
• Decide which techniques/views (from the UP or
web-specific) may be useful in your special case.
• Make a gross plan for the whole development
cycle.
• Make a detailed plan for the next phase.
• Keep to UP‘s phase structure and workflows but
vary the specific techniques and views found
relevant.
Links to resources regarding the UP
• Skriptum IT/SWE (Prof. Benkner)
(http://www.par.univie.ac.at/teach/02W/SWE/vo.html)
– UP Teil I: http://www.par.univie.ac.at/teach/02W/SWE/vo6.pdf
– UP Teil II: http://www.par.univie.ac.at/teach/02W/SWE/vo10.pdf
• Rational resources
– UP Home: http://www.rational.com/rup
– FAQ: http://www.rational.com/products/rup/faq.jsp
The Multiview Approach and
WISDM
• Multiview‘s fundamental assumption: An IS
methodology that relies overmuch on an
engineering approach and technical rationality is,
by itself, an insufficient foundation for IS
development.
• Foundations of Multiview: Needs of computer
artefacts, organizations and individuals need to be
considered jointly!
• Major concern of Multivies: Negotiation between
technological, organizational, and human aspects
of IS development.
WISDM as emerging methodology
from the Multiview framework
Humans
Organisation
Technology
ANALYSIS
SOCIO
Information
Analysis
Value creation
(human activity systems)
Requirements
specification
Work
Design
Technical
Design
User
satisfaction
HCI
TECHNICAL
Organizational
Analysis
Software
model
User interface
Situation
DESIGN
Developers
WISDM Methods matrix and role
of the analyst
• Moving around the methods matrix
– There is no a priori ordering of the five apects of the
WISDM matrix
• Multiview: How can any given instantiation of the
triad: analyst (change agent), methodology,
situation, come about in actual practice?
• Essential aspect: Analyst develop reflection and
self-awareness to become capable of thinking and
acting on the joint basis of the three (T, O, P)
perspectives.
Hard and soft systems thinking
• Traditional view of organisations:
Autonomous entities that seek to control their
environment while engaging in conflict and
competition with one another.
• Systems view (Soft Systems Methodolody):
The entire set of relationships that an organisation
has with itself and ist stakeholders.
– Organisations act as verbs rather than nouns;
– Organisations become active processes of maintaining
identity, relationships, and viability
Hard and soft systems thinking
Metaphors for organizations
Old organizational metaphor
Recast methaphor
organization as autonomous entity organization as a web of relations
among stakeholders
organizations enact and control
organizations thrive on chaos and
their environment
adapt to discontinuous change
conflict and competition
strategy as objective analysis
communication and collective
action
strategy as solidarity in relations
between agents and stakeholders
power and authority in hierarchies decentralization and
empowerment
(Vidgen, Tbl.6-1)
Hard and soft systems thinking:
traditions
The ‚hard‘ tradition
(Simon)
The ‚soft‘ tradition
(Vickers)
Concept of
organization
Social entities which set up and
seek to achieve goals
Social entities which seek to manage
relationships
Concept of
information
system
An aid to decision-making in
pursuit of goals
A part of interpreting the world, sensemaking with respect to it, in relation to
managing relationships
Underlying
systems
thinking
‚Hard‘ systems thinking: the
world assumed to be systemic
‚Soft‘ systems thinking: the process of
inquiry into the world assumed to be
capable of being organized as a system
Process of
research and
inquiry
Predicated upon hypothesis
testing; quantitative if possible
Predicated upon gaining insight and
understanding; qualitative
(Vidgen, Tbl.6-2)
Hard and soft systems thinking
basics
• With hard systems thinking a systematic approach is
taken to change real world systems.
• Soft approach: We do not maintain that the real world
contains systems. It is the intervention that is
organized systemically, the problem sitaution is
considered “messy“.
– Problem situation needs to be understood first
– Intervention is adapted to the particular problem situation
– Action to improve the problem situation is taken
SSM – Seven-stage model
(1) situation considered
problematic
(7) action to
improve the
problem situation
(6) changes:
systematically desirable,
culturally feasible
(2) problem situation
expressed
(5) comparison of
models and real
world
real world
(3) root definition of
relevant systems
(4) conceptual models
of systems described
in root definitions
systems thinking
about real world
(Vidgen, Fig. 6-2)
SSM – Seven-stage model
• Key issues:
– Division between above the line thinking ( =
real world) and systems thinking below the line
( = about the real world)
– Above the line: our perceptions about the
situation
– Below the line: models that help us gain insight
into the problem situation to foster debate and
to surface assumptions of stakeholders
– SSM frameworks are used loosely as guides for
an intervention rather than as a recipe book.
SSM: Situation considered
problematic (1)
• A problem or an opportunity may be the catalyst
for an intervention.
• Example:
Studying parents have hard times finding
affordable child-care options and financial support
to finish their studies in time. The university as
large organization could help by providing
focused information and contacts.
SSM: problem situation expressed (2)
• Rich picture diagram
– Representation of our mental model of the problem
situation to open it up for others
– Can be created collaboratively in a workshop
– Evolves over time
– May use some conventions:
• Crossed swords for conflict
• Stick figures for human actors
• Hurdles to represent difficulties
• Speech bubbles to represent opinions, …
SSM: problem situation expressed
(2) Example
SSM: Towards Root definitions of
relevant systems (3)
• Consider primary tasks and corresponding task
transformations.
• For each primary task consider issue-based
transformations that arise from competing or
complementary opinions of stakeholders.
• For each transformation find out, why it is
meaningful, i.e. find out the underlying
“Weltanschauung“ and potentially further issues
such as constraints, addressees, owners.
SSM: Root definitions of relevant
systems (3)
• Root definition:
– What will the system do (X)
– By means of what/whom will it do it (Y)
– Why it is meaningful for it to be done (Z)
• Template for a root definition:
– A system to do X by means of Y in order to Z
• Discuss:
What is the relationship between root definitions
and Use-Case and goal modeling?
SSM: Towards root definitions of
relevant systems (3)
Examples for task transformations:
Studying Parents T
Better supported
studying parents
Need for childcare T That need met
Time for studying
Questions
T
Contacts
T
T
Time for studying
enhanced
Timely responses to
questions
Contacts established
SSM: Towards root definitions (3)
Examples for issue-based transformations:
Disagreement over the
role of the university to
provide support
Understanding of needs
of studying parents
Disagreement over
allocation of resources to
support measures
T
Agreement on types of
support
T
better understanding of
studying parents‘ needs
T
Agreement on
allocation of resources
to individual initial
projects
SSM: Root definitions (3)
Examle for a root definition regarding the task
to support contacts:
Provision of a home page and a virtual
community (X) to be hosted at the
university and maintained by staff
development personell (Y), in order to
allow students and working parents to
establish contacts.
Conceptual activity model (4)
• Depicts the purposeful activities resulting from the
root definitions.
• Each activity can be decomposed and associated
with a root definition.
• Arrows between activities (subsystems) represent
logical dependencies.
• Monitoring and controlling are key activities due
to the iterative and incremental nature of soft
systems methodology.
Conceptual activity model (4)
Example in the context of UniKid:
Appreciate administrative
constraints
Appreciate constraints of
end-users
Appreciate what
constitutes support
Decide on types of
support to provide
Decide on
information to
provide and to link
Decide on webservices to provide
Administer the WebIS
Decide on physical
services to provide
Handle requests.
Conceptual activity model (4)
• Conceptual activity models are not models
of a real system.
• They help to organize thoughts about a
problem situation in a systemic manner.
• It is essential to develop more than one
model, where each model has ist own root
definition.
Monitoring and Control of
Transitions (4 cont‘d)
• Three success factors:
Efficacy
Efficiency
E1
E2
Effectiveness E3
Does it work?
Does it use minimal
resources?
Does it contribute to the
wider purpose?
Monitoring and Control of UniKid
• Efficacy: Do users get appropriate
information and support?
• Efficiency: How much time is needed to
maintain the system and the information,
and to respond to queries?
• Effectiveness: Are real contacts established?
Is the average studying time for students
reduced?
Comparison of models with real
world (5)
• The rigorous conceptual activity models are
compared with the messy real world
situation.
• Matrix:
– Rows: activities and logical dependencies
– Columns: Is the activity done already? If yes,
how is it accomplished? Comments and
recommendations.
Comparison of models with real
world (5)
Activity
1. Appreciate what constitutes
support
2. Decide on types of support to
provide
3. Decide on types of support to
provide
4. Appreciate constraints of endusers
5. Decide on real services to provide
Links 1 2
2  3 ...
Is it done in the real
situation? How is it
done?
How well is it
done? How is it
judged?
Comments and
recommenations
Comparison of models with real
world – considerations (ad 5)
• Essential note (to be discussed):
Large scale change can be achieved if it is
perceived as meaningful. While small scale
change and seemingly insignificant changes may
fail, because they are not perceived as meaningful
or necessary.
• As a consequence, SSM focuses on creating a
shared understanding as the basis for change that
will be considered as meaningful in the problem
situation!
Evaluating change and taking action
(6, 7)
• Hard systems thinking: change must be
systemically feasible and should be culturally
feasible.
• Soft systems thinking: change should be
systemically desirable, however, cultural
feasibility is of paramount importance.
• A SSM intervention is characterized by
– a genuine engagement with the problem situation
– the participation by those affected
– Cycles of learning
Evaluating change and taking action
(6, 7 cont‘d)
• Analysis 1: the intervention
Clarifying roles, comparing models of:
– Client (person who commissioned the study)
– Problem solver(s)
– Problem owner(s)
• The social system
– Analysis in terms of roles, norms, values
• The political system
– How is power expressed or achieved in the problem
situation? Does it come from formal authorities,
charisma, or external reputation?
To think about
• How can SSM be incorporated into the
development process?
– Front end to existing methodology?
– Use existing methodology just as another intervention?
– Tight integration with the Unified Process by providing
SSM views as part ot the analysis and design
workflows.
• Does (How does) SSM relate to the use-case
view?
Work design
ANALYSIS
SOCIO
Information
Analysis
Value creation
(human activity systems)
Requirements
specification
Work
Design
Technical
Design
User
satisfaction
HCI
User interface
DESIGN
Software
model
TECHNICAL
Organizational
Analysis
Sociotechnical design
• Foundation: Genuine participation:
involves users, managers, developers, and
others who influence each other‘s plans
policies and decisions, thus affecting future
outcomes.
• Role of the IS professional is altered: rather
than playing the role of the expert, he or she
has to work as a consultant to the design
group.
Sociotechnical design - Participation
• Three motivations to adopt a participative
approach:
– Those affected by an IS should have influence
on their destinies;
– Participation can build an involved and
committed work force;
– Participation is an educational experience that
provides insight , understanding and knowledge
that help an organization to better achieve their
policies.
Sociotechnical design – general
question
• Questions to be asked for any Web-IS
development project:
– Are the existing staff going to use the system? What for
will they use it?
– Will some staff be lost or redeployed?
– Will the good features of the existing system be kept,
e.g. job variety, easy interaction between people,
friendly working atmosphere,…?
– How important are criteria like improving job
satisfaction or acceptability by all employees?
Sociotechnical design - workflow
Set human objectives (improved job
satisfaction and quality of working life
Set efficiency objectives (improved business
efficiency and effectiveness)
Specify social alternatives (work organization,
job design)
Specify technical and administrative
alternatives (software, hardware, work
procedures, information flow)
Match as socio-technical alternatives
Rank in terms of ability of each
alternative to meet social and efficiency
objectives
Consider costs, resources, constraints
Select best socio-technical solution
(Vidgen, Fig. 7-4)
Participative design process
Designers learn about
work (several days)
Workplace visits with interviews and demonstrations of current work practices
Critique Phase
Future workshop
(2½ hours)
Fantasy Phase
Current roles and tasks
Organizational games
(2½ days + ½ day)
Users learn about new technology from illustrative mock-ups and prototypes
Changed roles and tasks
Action Plan
Embodying ideas
(weeks)
Mock-up design
Cooperative prototyping
(Vidgen, Fig. 7-5)
Participative design process workshops
• Future workshop:
– Lasts about half a day;
– Is facilitated to assure that all attendees have the
opportunity to contribute;
– It is possible that managers are not invited; (discuss)
– Critique phase:
• Brain storming session where current issues are addressed and
categorized
– Phantasy phase:
• Participants think about “what-if“ opportunities; what could be
different?
Quality workshop
• A group of users comes together and is asked: “What are
the qualities of an excelent …web site?“
• Attendees first work individually and write down
everything they can think of on post-it notes (one issue per
post-it). Issues will be qualities and functions.
• Attendees work then together in teams of 3-4 and look for
categorizations of their ideas (primarily qualities in this
context).
• A structured list of qualities is then produced that can be
rated against a range of qualities as well as importance.
• Alternatively, the WebQual instrument can be used for
rating.
Quality workshop, WebQual
Category
WebQual 4.0 Questions
Usability
1.
2.
3.
4.
5.
6.
7.
8.
9.
10.
11.
12.
13.
14.
15.
16.
17.
18.
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21.
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23.
Information
Service
Interaction
Overall
I find the site easy to learn to operate
My interaction with the site is clear and understandable
I find the site easy to navigate
I find the site easy to use
The site has an attractive appearance
The design is appropriate to the type of the site
The site conveys a sense of competency
The site creates a positive experience for me
Povides accurate information
Provides believable information
Provides timely information
Provides relevant information
Provides easy to understand information
Provides information at the right level of detail
Presents the information in an appropriate format
Has a good reputation
It feels safe to complete transactions
My personal information feels secure
Creates a sense of personalization
Conveys a sense of community
Makes it easy to communicate with the organization
I feel confident that goods/services will be delivered as promised
My overall view of this website
(Vidgen, Tab. 7-4)
Quality workshop,
WebQual