Requirements Engineering Onno de Graaf Unit 2: o.de.graaf at - PowerPoint PPT Presentation

9/ 8/ 2009 | 1 9/ 8/ 2009 | 2 Student assistant of RE 2009 fall Requirements Engineering › Onno de Graaf Unit 2: › o.de.graaf at gmail.com Requirements engineering process • coordinate the external and internal meeting during the tutorial session › Department of Computer Science / Peng Liang • answer the questions and requests posed by students, and › Rijksuniversiteit Groningen (RUG) • forward unsolved questions to me › http:/ / www.cs.rug.nl/ ~liangp/ teaching/ courses/ RE2009Fall/ Peng Liang Requirements Engineering 2009 Fall Peng Liang Requirements Engineering 2009 Fall 9/ 8/ 2009 | 3 9/ 8/ 2009 | 4 Grouping Course project deadlines › [Group 1]: Ruurd Krekt, Pim van der Waak, Henk van Ramshorst, › Deadlines Ralph van Brederode, Johan van der Geest, Mark Ettema  › Start working as group › [Group 2]: Erwin Vast, Fernand Geertsema, Marco Hak, Jop Verhagen, Mattijs Meiboom  • Propose projects › [Group 3]: Anton Jongsma, Dirk Nederveen, Karsten Westra, • Select projects Tom Spanjaard, Mark Scheeve, Edwin-Jan Harmsma  › [Group 4]: Chris de Wit, Eelco Hooghiem, Gertjan Dalstra, › REWiki instances created for each group Samuel Esposito, Artemios Kontogogos  › [Group 5]: Gerhard Boer, Jeroen de Groot, Tim van Elteren, Rudy Schoenmaker, Wilrik Mook, Pieter Stavast  › [Group 6]: Jochem Pastoor, Stef van Grieken, Jan Wijma, Wilco Wijbrandi, Joris de Keijser  Peng Liang Requirements Engineering 2009 Fall Peng Liang Requirements Engineering 2009 Fall

9/ 8/ 2009 | 5 9/ 8/ 2009 | 6 Cancel of the course next week Assignment of Week 36 › I am away for WICSA 2009 conference › SRS from small tools, plug-ins to very complex system › Course schedule will be postponed › Requirements range from functional, non-functional, to all kinds of requirements › I put some of best SRSs online for your reference • http:/ / www.cs.rug.nl/ ~liangp/ teaching/ courses/ R E2009Fall/ assignment/ Week36-SRS.zip Peng Liang Requirements Engineering 2009 Fall Peng Liang Requirements Engineering 2009 Fall 9/ 8/ 2009 | 7 9/ 8/ 2009 | 8 Your expectations / requirements Course outline Requirem ents Engineering › How to elicit correct user requirements ( elicitation ) › How to communicate with non-technical customers Requirem ents Engineering process ( elicitation ) Requirem ents elicitation › How to deal with conflicting requirements ( analysis, negotiation ) Requirem ents › How to prioritize requirements ( analysis ) docum entation Requirem ents Requirem ents › How to write understandable and testable SRS for negotiation analysis Requirem ents both developers and customers ( docum entation ) m anagem ent › How to manage requirements traceability ( m anagem ent ) Requirem ents validation Peng Liang Requirements Engineering 2009 Fall Peng Liang Requirements Engineering 2009 Fall

9/ 8/ 2009 | 9 9/ 8/ 2009 | 10 Last Unit Contents Basic of › What is a Process? Requirem ents Engineering This Unit › Why RE process? › General RE process model Requirem ents Engineering › Initiating an RE process process Next Unit Requirem ents elicitation Peng Liang Requirements Engineering 2009 Fall Peng Liang Requirements Engineering 2009 Fall 9/ 8/ 2009 | 11 9/ 8/ 2009 | 12 What is a Process? Why RE process? › An organized set of activities which transforms › Control of quality, schedule, and cost inputs to outputs › Complexity: human, social and organizational factors › Examples of process descriptions Qua lity of p rocess Qua lity of p rod uct activity • SCRUM process … input output Peng Liang Requirements Engineering 2009 Fall Peng Liang Requirements Engineering 2009 Fall

9/ 8/ 2009 | 13 9/ 8/ 2009 | 14 RE process: input and output RE process variability › RE processes vary from one organization to another Existing system information • Project scale Stakeholders • Organisational culture (XP, UP, SCRUM ...) concerns SRS • Application domain RE process Organizational • ... standards › No “ideal” or “uniform” Requirements Engineering Regulations and laws process Domain information › G. Kotonya and I. Sommerville. Requirem ents Engineering: A Good Practice Guide . John Wiley & Sons, 1997. Peng Liang Requirements Engineering 2009 Fall Peng Liang Requirements Engineering 2009 Fall 9/ 8/ 2009 | 15 9/ 8/ 2009 | 16 Buzz words on RE process Waterfall process › Activities: identification, elicitation, derivation, Elicitation analysis, definition, modeling, specification, Analysis documentation, communication, validation, negotiation, management, implementation, capturing, Validation discovering, structuring, representing, formulating … › Methods, means, tools, … Negotiation What steps Docum entation should I follow? Managem ent Peng Liang Requirements Engineering 2009 Fall Peng Liang Requirements Engineering 2009 Fall

9/ 8/ 2009 | 17 9/ 8/ 2009 | 18 Spiral process General RE process model Alternative proposals › Iterative process [Sommerville, 2005] Dom ain understanding Analysis & elicitation & negotiation spiral Start Consolidated Agreed requirem ents requirem ents Validation Specification & Quality assurance & docum entation waterfall Docum ented requirem ents › I. Sommerville . Integrated Requirem ents Engineering: A Tutorial . IEEE Software, 22(1):16-23, 2005. Peng Liang Requirements Engineering 2009 Fall Peng Liang Requirements Engineering 2009 Fall 9/ 8/ 2009 | 19 9/ 8/ 2009 | 20 Requirements elicitation Requirements analysis and negotiation › Obtain the requirements of a system from users, › Discover the bounds of the software customers and other stakeholders › Detect and resolve conflicts between requirements › Good requirements is not readily available from › Requirements prioritization & triage customers Peng Liang Requirements Engineering 2009 Fall Peng Liang Requirements Engineering 2009 Fall

9/ 8/ 2009 | 21 9/ 8/ 2009 | 22 Requirements validation Requirements documentation › Ensure SRS define the right system › Production of a document that can be systematically reviewed, evaluated, and approved • SRS reviews • See our SRS examples • Prototyping (GUI) • Model validation (Z lang) Peng Liang Requirements Engineering 2009 Fall Peng Liang Requirements Engineering 2009 Fall 9/ 8/ 2009 | 23 9/ 8/ 2009 | 24 Requirements management Initiate an RE process › Manage the requirements when evolves • change control How to start with elicitation? • Traceability management Peng Liang Requirements Engineering 2009 Fall Peng Liang Requirements Engineering 2009 Fall

9/ 8/ 2009 | 25 9/ 8/ 2009 | 26 Starting a project Starting points › Who are my Stakeholders ? Scope › What is the Scope ? › Is this project Feasible ? › Any Risks ? Starting a project in a right direction, Stakeholders then we can go step by step Peng Liang Requirements Engineering 2009 Fall Peng Liang Requirements Engineering 2009 Fall 9/ 8/ 2009 | 27 9/ 8/ 2009 | 28 Stakeholders Project world Environm ent contra ct Developm Usage ent world world b uild Project world System intera ct › M. Glinz and R.J. Wieringa . Stakeholders in Requirem ents Engineering . IEEE Software, 24(2):18-20, 2005. page 2 Peng Liang Requirements Engineering 2009 Fall Peng Liang Requirements Engineering 2009 Fall

9/ 8/ 2009 | 29 9/ 8/ 2009 | 30 Stakeholders analysis Example of stakeholder identification lecturer environ › Look for stakeholders associated with the project disorder m ent m aker world student • Usage, development, and environment usage nestor › Example stakeholders vendor Nestor teaching • End-users (usage) develop assistant system • Customers (usage) m ent • User support staff (development) university developer • Project manager (development) board • Negative stakeholders (environment) university nestor financial adm inistrators departm ent Peng Liang Requirements Engineering 2009 Fall Peng Liang Requirements Engineering 2009 Fall 9/ 8/ 2009 | 31 9/ 8/ 2009 | 32 Scoping - elicitation difficulties Examples - Automatic loan approval system › Lack of domain knowledge › The problem area • Context: Loan approval departm ent in a large bank • Public transportation system • Objective: The analyst tries to elicit the rules and › Tacit knowledge procedures for approving a loan • Incom e for credit card › Personal bias • Political, personal, background Peng Liang Requirements Engineering 2009 Fall Peng Liang Requirements Engineering 2009 Fall