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1. Lecture 02 Chapter 3 – Requirements Elicitation and Analysis ITEC 4040 – Requirements Management Prof. DawidKasperowicz http://www.yorku.ca/dkasper
2. Requirements Challenge Complex HCI: Always complicated and complex Eliciting Requirements Need to be always exploring May possible solutions No right or wrong What is the problem again? ITEC 4040 – Requirements Management
3. Once More: What is RE? A systematic process of developing requirements through an iterative and co-operative process of analyzing the problem, documenting the resulting observations in a variety of representation formats, and checking the accuracy of the understanding gained [MaCaulay – Requirements Engineering (applied Computing)] ITEC 4040 – Requirements Management
4. Software Myths (From Easterbrook Lectures) Cost of software is lower than the cost of physical devices Software is easy to change Computers are more reliable than physical devices Software can be formally proved to be correct Software reuse increases safety and reliability Computers reduce rick over mechanical systems ITEC 4040 – Requirements Management
5. Why do we Develop a Software? Competition, critical facts New technology has been developed New requirements Company is growing Business is changing Something changed in your world Continue a previous project ITEC 4040 – Requirements Management
6. A Place to Start Nowadays, there is almost always a system in place Studying what we currently have prompts to getting preliminary requirements and helps to avoid past mistakes Using what we have Can reduce costs Make it easer to break problems down But can misleading Is the problem that is presented to us the real problem? ITEC 4040 – Requirements Management
7. How Elicitation Fits? It is the first part of the requirements process It goes throughout the entire lifecycle– never stops ITEC 4040 – Requirements Management
8. Another Definition An externally observable characteristic of a desired system E.g.: A mouse needs 2 buttons If the user needs 2 buttons, this is a requirement If the user only needs a way of moving slides back and fourth, this is too detailed to be a requirement ITEC 4040 – Requirements Management
9. Basic Needs for Elicitation (Questions from Polya) What is unknown? Do you know any related problem? Can you reinvent the problem? ITEC 4040 – Requirements Management
10. Elicitation Elicit [Var. elicit + make it clearer + extract] Discover, make explicit, get as much information as possible to understand the object being studied Identify sources of information Gather facts Communication ITEC 4040 – Requirements Management
11. Elicitation Gathering information may be hard Communication can be difficult (different languages and knowledge) Stakeholder may be (often are) hard to meet They may have conflicting objectives Stakeholders often have different viewpoints regarding the same thing Knowledge is usually distributed among many different sources The presence of an outsider may change the process Hidden agendas Fear of change ITEC 4040 – Requirements Management
12. Dimensions of Requirements Elicitation Application domain understanding – Knowledge of the general area where the system is applied Problem understanding – Details of the specific customer problem where the system will be applied Business understanding – Knowing how systems interact and affect the different parts of the business and how they contribute to the business goals Understanding the needs and constraints of system stakeholders – Understanding their specific needs for system support in their work, the process that the system is intended to support and the role of existing systems in these work processes ITEC 4040 – Requirements Management
13. Identifying Sources of Information Actors in the Universe of Discourse Clients Users Developers Documents Books Software Systems COTS (Commercial off the Shelf) ITEC 4040 – Requirements Management
14. Who is Related to the Software? Non-clients Clients Third party clients Users Clients Customer Investor Owner Partner Interested Quality Control (QC) Technical Writers Software Engineer Developers ITEC 4040 – Requirements Management
15. Criteria Experience Knowledge about the domain Volume of investment What the stakeholder does daily ITEC 4040 – Requirements Management
16. Sources of Information ITEC 4040 – Requirements Management
17. Heuristics to Identify Sources of Information Who is the client? Who owns the system? Is there any customized system available? What are the books related to the application? Is it possible to reuse software artifacts? What are the documents most cited by the actors of the Universe of Discourse? ITEC 4040 – Requirements Management
18. Requirements Traceability It is about understanding how high-level requirements (objectives, goals, aims, aspirations, expectations, needs) are transformed into low-level requirements Allows us to analyse requirements using various methodologies and is at the heart of the requirements engineering process Traceability relationships are usually many-to-many Examples: In a business context, you’d want to know what the business visionis. This can be interpreted as business objectives and implemented as business organization and processes In an engineering context, you’d want to know what the stakeholder requirements are. These are met by system requirements and implemented as components ITEC 4040 – Requirements Management
19. Benefits of Requirements Traceability Greater confidence in meeting objectives – Establishing and formalizing traceability allows for greater reflection on how objectives are satisfied Ability to assess the impact of change – Allows the use of impact analysis methodologies with the presence of traceability information Improve accountability of subordinate organizations – Greater clarity of how suppliers contribute to the whole Ability to track progress – Difficult to measure progress when you are creating and revising documents without taking measures to trace them Ability to balance cost against benefit – Relating product components to the requirements allows benefits to be assessed against cost ITEC 4040 – Requirements Management
20. Where Requirements Come From Stakeholders – any person or organization that has an opinion, a responsibility for, or who may be influenced or affected by the proposed system People who have an opinion about the proposed system include those who will use it directly, and this can include the general public E.g.: Passengers on a transportation system, or those affected by a crash when they were otherwise not involved in travelling ITEC 4040 – Requirements Management
21. Types of Stakeholders Managers – People who have a responsibility for either the development budget or operating budget of the proposed system, senior policy makers, etc. Investors – People who either have made or are being invited to make a contribution to the funding of the proposed system or the organization responsible for developing or operating the system ITEC 4040 – Requirements Management
22. Types of Stakeholders System Users – Have a direct interest in the capabilities provided by the new system or service. There may be users who do not interact directly with the system Maintenance and Service Staff – Keep the system running once it has been delivered Product Disposers – Increasingly important as environmental protection legislation develops. Requirements from this source can have a massive impact on design especially with respect to the materials employed ITEC 4040 – Requirements Management
23. Types of Stakeholders Training Personnel – Have a vested interest in having great usability System Buyers – For public services or large systems, the person who buys the system may not be involved directly with its development or operation, but they will have an important role in scoping the system from the view point of cost vs. perceived benefit ITEC 4040 – Requirements Management
24. Types of Stakeholders Sales and Marketing – Have a vital role to play in formulating the capabilities for new systems, especially for product-based developments, because, for mass-produced consumer products, it is not possible to have access to all potential users Usability and Efficiency Experts – Have views on system optimization and efficient ITEC 4040 – Requirements Management
25. Types of Stakeholders Operational Environment Experts – Usually, the new system needs to inter-operate with existing systems and there may be other environmental aspects such as emission control, or tolerating the environment it is placed in Government – Rules, regulations and laws determine and influence what a system may or may not do Standards Bodies– Existing and future standards can affect the goals of a proposed system ITEC 4040 – Requirements Management
26. Types of Stakeholders Public Opinion and Opinion Leaders – Different regions of the world have different attitudes and they must be recognized where a product is to be marketed in a wide range of countries Regulatory Authorities – May require certain evidence be collected as part of a certification or authorization process ITEC 4040 – Requirements Management
27. Facts Gathering Document reading Observation Interviews Reunions Questionnaires Anthropology Active participation from actors Protocol analysis Reverse engineering Reuse ITEC 4040 – Requirements Management
28. Tacit Knowledge The kind of knowledge that is trivial for the actor being interviewed but not for the interviewer Because it is trivial, people almost never remember to mention it. Since no one but the interviewee knows about it, interviewers cannot ask about it ITEC 4040 – Requirements Management
29. Interviews Most used technique Should not be the only one Can be used for: Learning what the present system does What the stakeholders needs are Can be: Structured Unstructured ITEC 4040 – Requirements Management
30. Structured Interviews What to ask: Objective questions with precise targets One question should be related to the other How to ask Whom to ask Usually 1 on 1 Can be 1 to many or many to 1 Requires some knowledge about the problem to formulate the questions Tape it? ITEC 4040 – Requirements Management
31. Structured Interviews: Positives Assures you will organize your thoughts and activities before the interview Allows you to target specific things Easier to summarize the interview later Pushes stakeholders to be systematic Facilitates to remove distortion from interviewees subjectively ITEC 4040 – Requirements Management
32. Structured Interviews: Negatives Requires more time You need to have extensive (or at least good) knowledge of the business May result in leaving things unexplored that should have been explored May look like stakeholders are been “pushed against the wall” ITEC 4040 – Requirements Management
33. Non-Structured Interview More flexible Should still have a pre-defined guideline of questions Informal Remember to always keep control Mostly used during exploratory phases Can be used in later phases to solve conflicts or to further explore alternatives ITEC 4040 – Requirements Management
34. Non-Structured Interview: Positives Good when you are new to the business Can be used to explore ideas and doubts Usually the stakeholders feel better and many disclose more information Helps to see the “big picture” ITEC 4040 – Requirements Management
35. Non-Structured Interview: Negatives What you get may not be relevant to your system Hard to summarize findings Do not favour to obtain specific knowledge Not everybody can do it well – interviewing skills highly desirable Might lead you to repeat questions in the future (it can be quite annoying to be answering the same thing over and over) ITEC 4040 – Requirements Management
36. The Interview Process Prepare Carry Out Follow Up ITEC 4040 – Requirements Management
37. Interviews Follow Up – Essential After the interview write down what you understood Send it to the user(s) involved and ask for feedback (Have I got it right?) Ask if the user(s) want to add anything Positives: Direct contact with the actors Can validate information immediately Can target discoveries Negatives: Information coming from several sources can be hard to organize and often contradicting May intimidate the stakeholder Tacit knowledge Cultural differences ITEC 4040 – Requirements Management
38. Interviews - Tips Start the interview with some small talk. Try to set people at ease Easy questions always come first Personal information Organization/Sector structure Even if it’s a structured interview, probe for details when needed, but be careful not to get lost If the time allows, towards the end you can use open-ended questions: Is there anything else you think we should know about? ITEC 4040 – Requirements Management
39. Interviews - Tips Important to talk the stakeholder’s language about their world, not about the final product or any technical issues Good idea to ask the stakeholder to step through the process of their work Don’t be judgmental and repeatedly ask “why?” The only stupid question is the one that is not asked ITEC 4040 – Requirements Management
40. Interviews - Tips Interview every type of stakeholder (if possible)and take them seriously Document the interviews and invite the stakeholder to sign the record of the interview Attempt to discover the relative importance to the stakeholder of each requirement If vague about any requirement, ask for what is the purpose of the requirement and second ask how the proposed requirement could be demonstrated Enquire about any constraints the stakeholder is aware of Inform stakeholder their requirements will shape the system Process the notes into single requirements quickly, and then iterate ITEC 4040 – Requirements Management
41. Reading Books Summary per chapter Highlight the most important parts Use a key-word index Vocabulary Company reports Organization charts Policy manuals Job descriptions Documentation of existing systems Informal documents ITEC 4040 – Requirements Management
42. Reading Macrosystem documents (a more careful reading) Underline repeated words Synonymies Take note of unknown terms Search for relationships among terms Vocabulary Try to understand and document the structure of the documents ITEC 4040 – Requirements Management
43. Reading Macro system documents Understand the structure of the documents How they relate/point to eachother Reading similar documents Identify structures Relate structures Vocabulary ITEC 4040 – Requirements Management
44. Reading Positives Easy access to different sources of information Volume of information Helps you prepare to use other techniques Negatives Information can be very dispersed Considerable amount of work is required to identify relevant facts Written documents are often “late” Process change aren’t usually documented ITEC 4040 – Requirements Management
45. Questionnaires What should one ask? Asks for some knowledge about the problem Therefore you should have a minimum understanding about the problem Similar to structured interviews ITEC 4040 – Requirements Management
46. Questionnaires Types: Qualitative Allows the one answering more time to consider their answer Makes a later analysis more difficult Controlled questions – We can stimulate conflicts in order to verify the consistency of what is being told Quantitative Grading (Yes/No, Good/Medium/Bad, 0/1/…/5) Question has to be well formed to allow a good distribution of the answers ITEC 4040 – Requirements Management
47. Questionnaires Example Quantitative 8 – How easily can you retrieve information from Patient’s Medical Records? Number of Answers 5 – Do you think that it is important to allow recording more than two channels at the same time? (PVR Development) Number of Answers Not easily Easily No Yes ITEC 4040 – Requirements Management
48. Questionnaires Examples Qualitative What do you think are the major problems with the current workflow? What do you think would be necessary to improve your performance? What kind of information would you like to get? Why? ITEC 4040 – Requirements Management
49. Questionnaires Positives: Standard questions Statistical treatment possible Can reach a large number of people Can reach people virtually anywhere in the world Negatives: Answers are constrained Few or no interaction/participation Number of questionnaires returend can be disappointing Difficult to design Avoiding ambiguities What questions should I ask? How should I phrase them? ITEC 4040 – Requirements Management
50. Meetings An extension of an interview Direct and intense participation Short and intense periods Focus Types: Brainstorm JAD Requirements workshop Uses facilitators Previous planning ITEC 4040 – Requirements Management
51. Meetings Requirements workshops Preparation Adequate place Choosing participants Prepare the material ahead of time Agenda Facilitator Trained Team spirit Respected by all participants “Powerful” enough to make decisions when conflicts arise ITEC 4040 – Requirements Management
52. Meetings Requirements workshops During the meeting Relax participants Focus on ideas, not people Be open to brainstorming Register the meeting (minutes are highly desirable) Follow-up and schedule for next meetings ITEC 4040 – Requirements Management
53. Meetings Requirements workshops Problems People with a reign attitude Passive attitude People arriving late Negative/mocking comments It is always hard to resume a meeting after a disruptive interruption ITEC 4040 – Requirements Management
54. Meetings Requirements workshops Brainstorm Generate and condense ideas Frequently, the best ideas are combinations of two or more ideas Prioritize the ideas It is better to be done locally, but it is possible to have it over the web or using video-conferencing ITEC 4040 – Requirements Management
55. Meetings Requirements workshops Brainstorm Phase 1 – Generating Ideas Goal: Generate as much ideas as possible Rules Do not allow critics or debate at this point Let the imagination flow Change and combine ideas ITEC 4040 – Requirements Management
56. Meetings Requirements workshops Brainstorm Phase 2 – Reducing the number of ideas Discard ideas that are not worth to invest in Group ideas – make meaningful group names Annotate small descriptions about the rationale regarding the ideas and its authors Prioritize Vote Categorize: critical, important, useful ITEC 4040 – Requirements Management
57. Meetings JAD (Joint Application Development) – A special type of requirements workshop Involves Objectives System requirements External project ITEC 4040 – Requirements Management
58. Meetings JAD (Joint Application Development) Principles Group dynamic Visual resources Organized and rational process Documenting using the idea of “What you see is what you get” ITEC 4040 – Requirements Management
59. Meetings JAD (Joint Application Development) Target Identify high level (abstract) requirements Define and associate the scope Plan the activities for each phase of the project Post and approve resulting documents ITEC 4040 – Requirements Management
60. Meetings JAD (Joint Application Development) Phases Customization Meetings Present the tasks Join ideas Evaluate Compromise Closing ITEC 4040 – Requirements Management
61. Meetings JAD (Joint Application Development) Documents Requirements High level requirements Goals Anticipated benefits Strategies and future considerations Hypothesis and constraints Security, auditing and control System scope System users and their locations Functional areas outside the application Plans Participant matrix Identification of the JAD/PROJECT Estimative ITEC 4040 – Requirements Management
62. Meetings JAD (Joint Application Development) Used to speed up the investigation of system requirements, design a solution, define new procedures Critical Factor: To have all the relevant participants present Typically used for 3-6 months long projects Larger projects may require one JAD at the beginning of each iteration ITEC 4040 – Requirements Management
63. Meetings Positives: Gives the RE multiple options Collective work Negatives: Dispersion Cost ITEC 4040 – Requirements Management
64. Observation To watch people while they’re doing their jobs Take careful notes Be careful about Taping/Recording ITEC 4040 – Requirements Management
65. Observation Positives: Low cost Easy task (Sometimes) Negatives: Depends on the actor not being influenced because they know they are being observed Depends on the observer’s skills Tends to be superficial due to the weak exposition of the universe of discourse ITEC 4040 – Requirements Management
66. Protocol Analysis Analyze the work the person “beside” you is doing User speaks aloud during their tasks Some people claim during an interview/questionnaire/meeting one can use the memory instead of what he/she really does Goal – identify rationale used to perform a task ITEC 4040 – Requirements Management
67. Protocol Analysis Similar to observation but here, the users would talk aloud explaining what they are doing Positives: Elicit facts not shown Easier to avoid tacit knowledge Better understanding about tasks and rationales behind them Negatives: Focus on performance (sometimes) Not always what I say is what I do Might be hard to use in some environments (e.g., hospitals) ITEC 4040 – Requirements Management
68. Ethnography Deeply integrate to the environment The analyst becomes a client or even responsible for some tasks Slow Long term results Positives: Focus from the inside to the outside Contextualized Almost no tacit knowledge Negatives: Time Lack of systematization ITEC 4040 – Requirements Management
69. The End Questions? Lecture 02 ITEC 4040 – Requirements Management Prof. DawidKasperowicz http://www.yorku.ca/dkasper