1 / 58

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

oshin
Download Presentation

Web Information System Development

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Web Information System Development

  2. 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

  3. 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

  4. Building web applicationscitation 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.

  5. 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

  6. The four Worlds of Information Systems Subject world (Mylopoulos 92, Loucopoulos 95, Abb. 4.1, S. 73)

  7. 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.

  8. 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

  9. 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.

  10. 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

  11. 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)

  12. 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.

  13. 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

  14. 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.

  15. 6 UP Best Practices that particularly apply to web-based systems • 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

  16. 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.

  17. 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

  18. WUP – Complementing the UP For each phase: Inputs for each phase and iteration of the UP Web-specific activities are discussed in the following chapters UP–activities Web–specific activities

  19. 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.

  20. 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

  21. 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.

  22. ANALYSIS SOCIO Organizational Analysis Value creation (human activity systems) Information Analysis Requirements specification TECHNICAL WorkDesign User satisfaction HCI User interface TechnicalDesign Software model DESIGN WISDM as emerging methodology from the Multiview framework Humans Organisation Technology Situation Developers

  23. 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.

  24. 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

  25. Hard and soft systems thinkingMetaphors for organizations (Vidgen, Tbl.6-1)

  26. Hard and soft systems thinking:traditions (Vidgen, Tbl.6-2)

  27. Hard and soft systems thinkingbasics • 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

  28. SSM – Seven-stage model (7) action to improve the problem situation (1) situation considered problematic (6) changes: systematically desirable, culturally feasible (5) comparison of models and real world (2) problem situation expressed real world systems thinking about real world (4) conceptual models of systems described in root definitions (3) root definition of relevant systems (Vidgen, Fig. 6-2)

  29. 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.

  30. 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.

  31. 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, …

  32. SSM: problem situation expressed (2) Example

  33. 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.

  34. 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?

  35. SSM: Towards root definitions of relevant systems (3) Examples for task transformations: Studying Parents Better supported studying parents Need for childcare That need met Time for studying Time for studying enhanced Questions Timely responses to questions Contacts Contacts established T T T T T

  36. SSM: Towards root definitions (3) Examples for issue-based transformations: T T T

  37. 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.

  38. 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.

  39. 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 physical services to provide Decide on web-services to provide Decide on information to provide and to link Administer the Web-IS Handle requests.

  40. 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.

  41. Monitoring and Control of Transitions (4 cont‘d) • Three success factors:Efficacy E1 Does it work?Efficiency E2 Does it use minimal resources?Effectiveness E3 Does it contribute to the wider purpose?

  42. 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?

  43. 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.

  44. Comparison of models with real world (5)

  45. 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!

  46. 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

  47. Evaluating change and taking action (6, 7 cont‘d) • Analysis 1: the interventionClarifying 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?

  48. 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?

  49. ANALYSIS SOCIO Organizational Analysis Value creation (human activity systems) Information Analysis Requirements specification TECHNICAL WorkDesign User satisfaction HCI User interface TechnicalDesign Software model DESIGN Work design

  50. 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.

More Related