CCU 2010 / Identifying User Needs and Establishing Requirements. Lesson 7. (Part1 Requirements & Data Collection)

Transcription

1 CCU 2010 / 2011 Lesson 7 Identifying User Needs and Establishing Requirements (Part1 Requirements & Data Collection)

2 Previous Lesson (1) Participative Design Users are active in Developing Discussing and deciding IST, RP & JB 2

3 Previous Lesson (2) Topics Who represents the users? How to facilitate the communication between different user groups? Sharing representations Cultural differences Cooperative design Cooperative evaluation IST, RP & JB 3

4 Previous Lesson (3) Techniques PICTIVE CARD Card Sorting Six Thinking Hats Acting out IST, RP & JB 4

5 Introduction Requirements: What, How, Why Requirements Data collection Interpretation and analysis Task description Task analysis IST, RP & JB 5

6 A short story IST, RP & JB 6

7 Identifying Needs and Requirements When? Substituting / Updating an existing product Creating a new product What should the product provide? There are already some requirements Refine existing requirements Create new set of requirements from scratch IST, RP & JB 7

8 From Needs to Requirements Users have Needs Wishes Expectations Difficulties That need be Discussed Refined Clarified Reviewed IST, RP & JB 8

9 How to Get Good Requirements Implies Understand the users Know users capacities and skills Know the tasks they carry out and their objectives Know under which conditions tasks are carried out Know which product(s) they use Know the constraints in the use of the product(s) IST, RP & JB 9

10 How to Identify Requirements Identify User needs Stating requirements Set of requirements is not a wish list Do no isolate / put users away They are needed for the several evaluation and design cycles IST, RP & JB 10

11 Introduction Requirements: What, How, Why Requirements Data collection Interpretation and analysis Task description Task analysis IST, RP & JB 11

12 Requirements: What? Attain 2 objectives Gather data on Users Work / activity context User Needs The design cycle path Data > Requirements > Design IST, RP & JB 12

13 Requirements: How? How? Gather data Interpret data Analyse data Stating requirements Requirements specification and documentation Iterative refinement process Do not put users out of the loop! IST, RP & JB 13

14 ( 1 ) Why? Requirements: Surveys and studies show that Bad requirements are one of the main factors behind many products failure Successful products are the outcome of clear and detailed requirements Establishing requirements is a critical activity of the development process IST, RP & JB 14

15 ( 2 ) Why? Requirements: User Centred Design Is a way to get correct requirements That answer user needs and expectations IST, RP & JB 15

16 Establishing Requirements Requirements engineering Requirements identification ( products Existing (in other Capture requirements With the help of the various stakeholder groups Requirement analysis Classification, conflict resolution, consistency Reformulation Requirements validation Confirmation IST, RP & JB 16

17 Identifying Requirements It is not easy because Requirements are not self evident Users do not always know what they really want User may not be able to express themselves clearly User tell needs and wishes, not requirements IST, RP & JB 17

18 Identifying Requirements It is not easy because (cont.) Different user groups tell things differently External factors (business procedures, legislation, etc.) Requirements may be unrealistic or not in line with the application context IST, RP & JB 18

19 Introduction Requirements: What, How, Why Requirements Data collection Interpretation and analysis Task description Task analysis IST, RP & JB 19

20 ( 1 ) What is a Requirement From the dictionary Necessary condition Legal rule IST, RP & JB 20

21 ( 2 ) What is a Requirement Statement of what a product Should do How to do it Under which conditions Must be Specific Clear Without ambiguity Specification and documentation IST, RP & JB 21

22 Requirements: Examples All pages of the WWW site must load in less than 5 seconds The product must be attractive to users You need to know what attractive means to the users IST, RP & JB 22

23 The Volere Model (Robertson, 2006) IST, RP & JB 23

24 Example of a Specification (1) Description: An alarm must always be raised when the RPU stops transmitting any messages Rationale: A loss in data transmission signals the likely malfunction of the substation, maintenance must be called in, and prevents visualizing and controlling all equipments located upstream Source: National grid control IST, RP & JB 24

25 ( 2 ) Example of a Specification Fit Criterion: The product will raise an alarm at all times that the number of messages per minute with origin from the RPU is less than the number set for that RPU Customer Satisfaction: 3 Costumer Dissatisfaction: IST, RP & JB 25

26 ( 3 ) Example of a Specification Dependencies: None Supporting Materials: RPU configuration and Operation Manual History: Raised by F. Fernandes, 2009/10/ IST, RP & JB 26

27 ( 1 ) Types of Requirements Functional What the product must do Ex.: image viewer must be able to read files written in several image formats Ex.: Product to support pointer and sweep interaction input devices IST, RP & JB 27

28 ( 2 ) Types of Requirements Non functional Constraints to the product and/or its development ex.: product to be portable to a list of hardware/ software platforms ex.: product to run on platforms with hard drives with 30 MB capacity ex.: product to be delivered in 6 months IST, RP & JB 28

29 Requirements in Interactive Systems Functional Data Environmental User Usability IST, RP & JB 29

30 Functional Requirements What the product must deliver Supported tasks Roles taken Examples: Warn that the inventory is low (under a predefined number of units) Prompt for input of mandatory data that was not supplied IST, RP & JB 30

31 Data Requirements Characterization of data produced (output) and data consumed (input) Type, volatility, volume persistency, update Examples: Share dealing application data must be accurate and up-to-date and may change many times a day Banks: data persistency over months/years IST, RP & JB 31

32 Environment Requirements Environmental Conditions under which the system must operate Physical: lighting, noise, dust, heat, humidity Social: resource sharing (files, equipments, synchronicity) Organizational: available support, training, (communication ) infrastructures, organization culture and structure Technological: platforms, compatibility, portability, technological constraints IST, RP & JB 32

33 User Requirements User characteristics capture Capacities and skills Difficulties Experience User profile Examples: Users must first know the Internet before accessing a WWW site System to be used by persons with motor disabilities IST, RP & JB 33

34 Usability Requirements Usability goals and related measurements Efficiency Efficacy Utility Satisfaction Learning Security Assess development progress IST, RP & JB 34

35 Exercise List some requirements for the following applications Estimation of the ecological footprint of a family Performance analysis and display of sports data IST, RP & JB 35

36 Introduction Requirements: What, How, Why Requirements Data collection Interpretation and analysis Task description Task analysis IST, RP & JB 36

37 Data Gathering Questionnaires Interviews Groups and Workshops Observation Prototyping Documentation Previous / similar systems IST, RP & JB 37

38 Data Gathering Examples Observation Provides understanding of the business process Participative prototypes (developed hand-in-hand with stakeholders) Use, explore and identify users knowledge Interviews (enable) Decision sequences capture and understanding Dialogue for negotiation between users and the development team Role playing prototypes (and walkthroughs) Idem IST, RP & JB 38

39 Data Gathering - Prototyping Keep in touch with the application Enables the gathering of requirements that would not be otherwise visible Requirements for innovative systems / applications Observation in realistic scenarios impossible Very useful to validate / confirm requirements Explain usage scenarios IST, RP & JB 39

40 Data Gathering - Documentation Manuals Procedure manuals Business / operational rules User records / logs Good to identify Activities and related rules / procedures Legislation and contextual data Should never be the only data source Does not involve users (directly) IST, RP & JB 40

41 Data Gathering Previous Systems Assess what users have been using Assess similar (competing) systems May be a way to start understanding user difficulties Pay attention: what other systems provide is not necessarily good! Always check back with the users IST, RP & JB 41

42 Data Gathering Techniques Selection (1) Data gathering techniques main differences Time taken Level of detail Risk (incertitude) of conclusions Analyst experience IST, RP & JB 42

43 Data Gathering Techniques Selection (2) Type of tasks to identify / analyze Sequential tasks or concurrent / parallel tasks? Huge and complex data content or small and simple? User characteristics Ordinary persons with little training or task experts? IST, RP & JB 43

44 ( 1 ) Data Gathering Problems Identify and involve the stakeholders: Users, managers, technicians, consumer reps? Union reps? Shareholders? Getting stakeholders involvement: Workshops, interviews, workplace environment studies Get real users, not managers: A traditional software engineering problem IST, RP & JB 44

45 ( Problems(2 Data Gathering Requirements management: Version and propriety control Communication Within the development team With the client / user Between users (organization divisions that use different technologies) Implicit and distributed knowledge of the domain Difficult to get and understand Knowledge discourse Availability of key persons IST, RP & JB 45

46 ( Problems(3 Data Gathering Political problems within the organizations Domination exerted by a group of stakeholders Changes in the business or economic environment Balance between functionality and usability IST, RP & JB 46

47 Data Gathering: Recommendations (1) Target data gathering at identifying stakeholders Behaviour, tools, other products, previous versions Involve user groups Workshops, interviews, observation A representative of each group is not enough Managers neither too IST, RP & JB 47

48 Data Gathering: Recommendations (2) Combine several techniques Each technique provides a different view Different views > corroboration Interviews, surveys > consolidate with workshops Use materials at all times Prototypes, descriptions, etc IST, RP & JB 48

49 Data Gathering: Recommendations (3) Prepare all activities well Test tools Know what you want to get Balance data gathering and analysis Plan how to gather data adequately Analyze as early as possible IST, RP & JB 49