470 likes | 632 Views
CSE 5316/7316 Software Requirements Fall 2013 Computer science Department, Lyle school of engineering, SMU. WinWin Negotiation tools. Naseer Jan. Course Instructor : Dr. Huang. Pervasiveness of Software. Software-intensive systems prevalent across industries/domains
E N D
CSE 5316/7316Software Requirements • Fall 2013 Computer science Department, Lyle school of engineering, SMU WinWin Negotiation tools Naseer Jan Course Instructor : Dr. Huang
Pervasiveness of Software • Software-intensive systems prevalent across industries/domains • E.g.: automotive, finance, consumer electronics, medical devices etc., • Information systems: • Collects, stores, transforms, transmits, and/or processes information or data • Goal: Provide information at right place/time • Ex.: Accounting system • Embedded software-intensive systems: • Software only ONE (important) part of overall system • Often closely integrated with hardware • Ex.: Anti-lock braking system of a car
Challenges in Software Development • Software-based innovations • Customers demanding innovative features software is key for realizing innovation • Increasing Complexity • Greater number of functions realized by software increasing complexity i.e., increased integration with external systems, customizability etc., • Higher quality demands • Pervasiveness of software higher level of quality • Shorter development times • Increasing competition faster time to market • Pressure to reduce costs • Increasing market pressure software systems must be developed at lower costs
Project Success Rate Challenged: Over budget/schedule or undelivered projects Failed: Cancelled projects
CHAOS ’10 – Factors Influencing Project Success • User Involvement • Executive Support • Clear Business Objectives • Emotional Maturity • Scope Optimization • Agile Process • Project Management Expertise • Skilled Resources • Execution Capability • Tools and Infrastructure Lack of Stakeholder involvement and convergence viewed as major causes of project failure
Why Is RE Important? • Flawed requirements a major cause of project failure • Fixing an error in later phases 10x more expensive • Incorrect requirements ↔ Incorrect system leads to wasted costs • System maybe unreliable for practical use disrupting normal day-to-day operations • The primary vehicle for going from “vision” to “realization”
RE and the Enterprise Marketing Market needs and trends, Price range New Features Requirements Engineering Product roadmap/ strategy, key requirements Realized changes and enhancements Product Management Customer Relationship Management New and revised requirements Customer wishes, Reported problems
RE and Software Development Project plan, Approved goals Requirements & constraints Project Management Design & Development Monitoring data, Elicited goals Solutions, New technologies Requirements Engineering Requests for clarification and improvement Status of change requests Quality Assurance System Maintenance Requirement Artifacts Change requests
Types of Requirements • Functional Requirements: specify the functionality the system shall provide to its users • Ex.: The system shall allow the users to access their profile page after they provide valid credentials • Quality Requirements (a.k.a., Levels of Service): define the quality properties of the entire system or of a system component, service or function • Ex.: Reliability, performance under high loads etc., • “-ilities”: Availability, flexibility, scalability, usability, robustness, interoperability etc., • Constraints: Organization or technological requirement that restricts a way in which the system shall be developed • Ex.: Legal constraints (Sarbanes-Oxley), Project/Budget/ Schedule constraints, Physical constraints etc.,
Goal of RE: Establishing a Vision in Context • Requirements Engineering processes start with an aim tochange current reality • Vision: (a.k.a “system vision”) • Essence of desired change defined briefly and precisely • Describes overall goal(s) of the system • Usually associated with particular point in time of when the vision should be realized • Serves as a guide during development for all Success Critical Stakeholders (SCS) involved in the project
Goal of RE: Establishing a Vision in Context • Each system is embedded within a given context • Context (a.k.a. “system context”): Part of the system environment relevant for • Defining, understanding & interpreting system requirements
Visualizing “Vision” in “Context” • Establish system vision within existing system context • Deal with parts of the real world that are relevant and their relation to the development context Vision defines focus
Framework For RE System Context Validation Core Activities Management Requirements Artifacts
Framework For RE System Context Subject FacetMaintain information about objects/events in the real world. Usage Facet Desired workflows, usage goals, different user groups, interaction models, laws & standards etc., IT System FacetExisting hardware, software, communication networks, peripheral devices etc., Development FacetProcess guidelines and constraints, QA methods, maturity models, development environments etc.,
Relationship Between Facets IT System Facet Subject Facet Representation Presentation Application Usage Facet Development Facet RE happens here!!
Three Dimensions & Goalsof Requirements Engineering • Content: • All relevant requirements are explicitly known and understood at the required level of detail • Agreement: • A sufficient agreement about the system requirements is achieved between the success critical stakeholders • Documentation: • All requirements are documented and specified in compliance with the relevant documentation/specification formats & rules
Visualizing The “Three Dimensions” Content Goal complete Agreement consolidated views vague individual views Documentation informal compliant with rules
Framework For RE Core Activities Documentation Document & specify elicited requirements as per defined documentation and specification rules. Also capture rationale and other relevant information Negotiation1.Detect conflicts and make them explicit 2. Resolve identified conflicts Elicitation
Framework For RE Elicitation Identifying Requirement SourcesStakeholders Existing Documentation Existing System(s) Developing new & innovative requirementsTypically not elicit-able and require collaborative and creative processes Elicit Existing Requirements Elicit already “known” requirements from relevant sources
Techniques For Elicitation • Interviews • Workshops • Focus Groups • Observation of stakeholders/users etc., • Questionnaires • Perspective-based reading Usually supported by “Assistance Techniques” • Brainstorming • Prototyping • Mind Mapping • KJ Analysis/Method • Elicitation Checklists
Framework For RE Requirements Artifacts (Documented Requirements) Goals Stakeholder intention with regard to the objectives, properties or use of the system Scenarios Positive/Negative, Misuse, Exploratory, Current-state/desired state, Main, alternative or exception Solution oriented requirementsData Model, Functional Model, Behavioral Model
Framework For RE • Validation of context consideration Check whether all relevant aspects in 4 contexts have been elicited, documented within the RE process • Validation of execution of activities Check adherence of activities to process, standards, guidelines etc. • Validation of requirement artifacts Check documented requirements w.r.t. content, documentation and agreements Validation
Validation Techniques • Inspections • Walkthroughs • Desk-checking (checking programs with pen-paper) • Prototyping Above are usually assisted by: • Validation checklists • Perspective-based reading • Verbalization of models • Creation of artifacts
Framework For RE • Observation of system context Identification and management of context changes • Management of RE activities Monitoring, controlling and adjustment of planned workflow of elicitation, documentation, negotiation and validation activities – standard project management • Management of requirements artifacts • Establishing traceability between different artifacts • Prioritizing requirements • Managing changes via change management processes Management
RE Framework == VBSE 4+1 • RE Framework advocated by Klaus Pohl is, in essence, isomorphic to VBSE’s 4+1 • VBSE brings value considerations to the foreground; RE Framework doesn’t seem to make it explicit • Each of the ‘steps’ of the RE framework is traceable in VBSE’s 4+1 structure (and vice versa)
Theory-W STOP THIS MADNESS! Customer Dr. Boehm Think of requirements as stakeholder negotiated win conditions!! Developer As a team discuss what will make each of you “win” (a.k.a. win conditions) Reach a mutual consensus and move forward (WinWin Equilibrium) Identify any issues and come up with options to resolve them
VBSE 4+1 • Theory W -“which values are important?” and “how is success assured?” for a given software engineering enterprise. • Utility theory (how important are the values?) • Decision theory (how do stakeholders’ values determine decisions?) • Dependency theory (how do dependencies affect value realization?) • Control theory (how to adapt to change and control value realization?).
WinWin Negotiation tools Evolution • The first generation of WinWin requirements negotiation support system was developed at USC in 1994 • Easy WinWin: is the fourth generation implementation for the WinWin requirements negotiation approach based on a Group Support System • Wiki WinWin: The WikiWinWin approach includes a stakeholder collaboration process and corresponding support tools. The WikiWinWin creates a sequence of steps and instructions to guide the stakeholders working out mutually satisfactory requirements. • Winbook: A Social Networking Based Framework for Collaborative Requirements Elicitation and WinWin Negotiations
WinWin Negotiation tools Evolution • What is EasyWinWin? • EasyWinWin is a requirements definition methodology that builds on the win-win negotiation approach and leverages collaborative technology to improve the involvement and interaction of key stakeholders. With EasyWinWin, stakeholders move through a step-by-step win-win negotiation where they collect, elaborate, and prioritize their requirements, and surface and resolve issues to come up with mutually satisfactory agreements • The WinWin negotiation model defines 4 types of artifacts – Win Condition, Issue, Option, and Agreement (WIOA)
WinWin Negotiation tools Evolution • Activities • Review and expand negotiation topics • Brainstorm stakeholder interests • Converge on Win Conditions: • Capture a glossary of Terms • Prioritize Win Conditions • Reveal Issues and Constraints • Identify Issues, Options • Negotiate Agreements
WinWin Negotiation tools Evolution • Review and expand negotiation topics
WinWin Negotiation tools Evolution • Brainstorm stakeholder interests
WinWin Negotiation tools Evolution • Converge on Win Conditions:
WinWin Negotiation tools Evolution • Prioritize Win Conditions • Reveal Issues and Constraints • Identify Issues, Options • Negotiate Agreements
Wiki WinWin • A wiki is actually two things: a program that makes it exceptionally easy for people to edit web pages and a philosophy regarding how users should go about the editing of web pages • A wiki has several key characteristics, which make it different from the other widely used collaborative technologies, e.g., discussion forums, weblogs, and GSS (group support systems) • It uses simple syntax and conventions to allow users easy editing or organizing of web pages • It enables web documents to be authored collectively without individual ownership of the document • The wiki can preserve the revision history, allow new information to update, and overwrite the old version • Wiki in general makes a basic assumption of the goodness of people. It allows content to be immediately published upon being saved. And it relies on the community of users to catch malicious content and correct it
Wiki WinWin • Many wiki engines are good in supporting collaboration activities e.g. the popular MediaWiki and TWiki. The Wikipedia, built upon the MediaWiki wiki engine, is one of the most well known cases. It’s an online encyclopedia, collaboratively written by a group of about 50,000 volunteers. • Yahoo uses TWiki internally to manage documentation and project planning; Disney uses TWiki as the central resource for ideas, notes, how to’s, specs, and brainstorming; and SAP uses TWiki for multi-team collaboration.
Wiki WinWin • The WikiWinWin • The WikiWinWin approach includes a stakeholder collaboration process and corresponding support tools. The WikiWinWin creates a sequence of steps and instructions to guide the stakeholders working out mutually satisfactory requirements. • Ease of use • Maintain the WIOAs • Guidance for negotiation process • Support of synchronous collaboration • Versioning across several pages
Putting It All Together Winbook Theory - W Requirement Specifications User Stories Gmail Facebook
Winbook • A collaborative, social networking based tool for requirements brainstorming similar to facebook… • …with requirements organization using color-coded labels similar to Gmail… • …to collaboratively converge on software system requirements reaching win-win equilibrium (based on Theory-W)… • …by keeping it short and simple like XP’s user stories!
Tutorial • http://www.youtube.com/watch?v=xFUj9Gj5XTU&feature=youtu.be