University of Toronto Department of Computer Science University of Toronto information acquisition Department of Computer Science Lecture 3 starting points Last Last Week Week Context Contextfor forRE RE What WhatisisEngineering Engineering Lifecycle Lifecycle models models Systems SystemsThinking Thinking This This Week Week Initiating Initiating an an RE RE process process Stakeholders Stakeholders and and Boundaries Boundaries Goals and Goals and Scenarios Scenarios Feasibility Feasibility and and Risk Risk Next Next Week Week Elicitation Elicitation Techniques Techniques Interviews Interviews Questionnaires Questionnaires Cognitive Cognitiveapproaches approaches Ethnography Ethnography 2000 2003 Steve Easterbrook 1 University of Toronto Department of Computer Science 2000 2003 Steve Easterbrook University of Toronto Starting Points Stakeholders Boundaries Subject World Goals and Scenarios Uses A useful way to organise initial collection of information Feasibility How to conduct a feasibility study How to choose which project to persue Maintains information about Needs information about How do you scope the problem Department of Computer Science The four worlds Importance of Customer Links Who are the stakeholders 2 System World Usage World Risk builds contracts Continuous Risk Management Identifying risks through hazard and fault analysis Development World 2000 2003 Steve Easterbrook 3 2000 2003 Steve Easterbrook Source Adapted from Loucopoulos Karakostas 1995 p73 4 University of Toronto University of Toronto Department of Computer Science Department of Computer Science Finding out about the four worlds Stakeholders Subject World Identify all the people who must be consulted during information acquisition Look for stakeholders associated with each of the four worlds the subject matter of the information system e g customers accounts transactions for a bank information system Usage World concerned with the features and functionality of the new system e g people such as managers clerks customers also business processes such as handling a withdrawal a deposit of foreign currency Designers want to build a perfect system or reuse existing code Systems analysts System World want to get the requirements right what the system does within its operational environment what information it contains and what functions it performs Training and user support staff want to make sure the new system is usable and manageable Business analysts e g system records all transactions in a database reports on transactions for a particular account gives account balance Example stakeholders Users the environment within which the planned system will operate Stakeholder analysis want to make sure we are doing better than the competition Technical authors Development World will prepare user manuals and other documentation for the new system The project manager the development process team schedule required qualities security performance etc wants to complete the project on time within budget with all objectives met the customer e g system to be delivered in 12 months fully tested to MCDC standard etc 2000 2003 Steve Easterbrook whoever it is that pays for the new system 5 University of Toronto 2000 2003 Steve Easterbrook University of Toronto Department of Computer Science Links with customers packages 70 Feedback from testing custom s w More Successful Project Less Successful Project Interviews Type of customer Link 60 50 40 30 20 Requirements Prototyping User Interface Prototyping Focus Groups Trade Shows User Groups On site customer representative 2000 2003 Steve Easterbrook Source Adapted from Keil and Carmel 1995 p37 C3 C4 C5 Custom Package Usability Lab manuf of elec goods C2 medium beverage co C1 major hotel chain P11 Company major airline P10 large comp company P9 a telecoms company P8 s w div of h w co P5 office auto devel P3 manuf s w devel P2 financial s w devel P1 prog env developer Observational Study CASE tool developer 0 E mailing list or bulletin board Facilitated Workshop e g JAD 10 software tool devel Links used as a percentage of all possible links Customer Support Line Marketing and Sales Involvement From Keil Carmel CACM May 1995 80 Department of Computer Science Customer Developer Links Successful projects tend to have more links with customer s UNIX tool supplier 6 C6 Survey 0 2 4 6 8 10 12 Number of Projects using this type of link 17 projects total 7 2000 2003 Steve Easterbrook 8 University of Toronto University of Toronto Department of Computer Science Department of Computer Science Difficulties of Elicitation Example Thin spread of domain knowledge The knowledge might be distributed across many sources Loan approval department in a large bank The analyst is trying to elicit the rules and procedures for approving a loan It is rarely available in an explicit form I e not written down There will be conflicts between knowledge from different sources People have conflicting goals People have different understandings of the problem There is no document in which the rules for approving loans are written down Conflicting information Different members of the department have different ideas about what the rules are Descriptions may be inaccurate rationalizations of expert behaviour Limited Observability Say do problem The loan approval process described to you by the loan approval officers is quite different from your observations of what they actually do The problem owners might be too busy solving it using the existing system Presence of an observer may change the problem Probe effect E g the Probe Effect and the Hawthorne Effect Why this might be difficult Implicit knowledge Tacit knowledge The say do problem People find it hard to describe knowledge they regularly use The problem area The loan approval process used by the officers while you are observing is different from the one they normally use Bias Bias People may not be free to tell you what you need to know The loan approval officers fear that your job is to computerize their jobs out of existence so they are deliberately emphasizing the need for case by case discretion to convince you it has to be done by a human Political climate organisational factors matter People may not want to tell you what you need to know The outcome will affect them so they may try to influence you hidden agendas 2000 2003 Steve Easterbrook University of Toronto 9 Department of Computer Science 2000 2003 Steve Easterbrook University of Toronto