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8/3/2019 APSI 10 Requirement Discovery Rev 2510011
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Requirement Discovery
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Introduction to Requirements
Discovery
Its important to design, construct andimplement a system effectively
Have to identify, analyze, and understand
what user requirement are
Involves system analyst, owners, user.
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the process and techniques used by systems
analysts to identify or extract system problems
and solution requirements from the user
Requirement specify what IS must do or what
property or quality the system must have.
Functional requirementNon functional requirement
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Results of Incorrect Requirements The system may cost more than projected.
The system may be delivered later than promised. The system may not meet the users expectations and
that dissatisfaction may cause them not to use it.
enhancing the system may be excessively high. The system may be unreliable and prone to errors and
downtime.
The reputation of the IT staff on the team is tarnishedbecause any failure, regardless of who is at fault, willbe perceived as a mistake by the team.
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Relative Cost to Fix an Error
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Criteria to Define System Requirements
Consistent requirements are not conflicting or ambiguous.
Complete requirements describe all possible system inputsand responses.
Feasible requirements can be satisfied based on the available
.
Required requirements are truly needed and fulfill the
purpose of the system.
Accurate requirements are stated correctly.
Traceable requirements directly map to the functions andfeatures of the system.
Verifiable requirements are defined so they can be
demonstrated during testing.6-6
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The Process of Requirements
Discovery
Problem discovery and analysis
Requirements discovery
Documenting and analyzing requirements
Requirements management
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Ishikawa Diagram (Problem Discovery
and Analysis)
The Ishikawa diagram is a graphical tool used
to identify, explore, and depict problems andthe causes and effects of those problems. It is
- -
diagram or a fishbone diagram.
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Requirements Discovery
Given an understand of problems, the systems
analyst can start to define requirements.
-
research, meetings, interviews, questionnaires,
sampling, and other techniques to collect
information about system problems,
requirements, and preferences. It is also called
information gathering or data collection.
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Fact-Finding Ethics Fact-Finding often brings systems analysts into contact with
sensitive information.
Company plans Employee salaries or medical history Customer credit card, social security, or other information
Ethical behavior includes:
Systems analysts must not misuse that information.
Systems analysts must protect that information from people who wouldmisuse it.
Otherwise: Systems analyst loses respect, credibility, and confidence of users and
management, impairing ability to do job Organization and systems analyst could have legal liability Systems analyst could lose job
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Seven Fact-Finding Methods
Sampling of existing documentation, forms,
and databases. Research and site visits.
.
Questionnaires.
Interviews.
Prototyping. Joint requirements planning (JRP).
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Documenting and Analyzing Requirements
Documenting the draft requirements with various tools
Analyzing requirements to resolve problems of:
Missing requirements Conflicting requirements
Infeasible requirements
Overlapping requirements Ambiguous requirements
Formalizing requirements
Requirements definition document
Communicated to stakeholders or steering body
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A requirement definition should contain :
Function and services the system should provide
Non functional requirement
Information about other systems with which the
system must interface
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Sample Requirements Definition
Outline
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Requirements Management
Requirements management - the process of
managing change to the requirements.
Over the lifetime of the ro ect it is ver common
for new requirements to emerge and existingrequirements to change.
Studies have shown that over the life of a project
as much as 50 percent or more of therequirements will change before the system is putinto production.
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Sampling of Existing Documentation, Forms, and
Files
Sampling the process of collecting a representativesample of documents, forms, and records.
Organization chart
Interoffice memoranda, suggestion box, customer complain
Accounting record, performance review work measurementrev ew
IS Project request
Standard operating procedures for current system
Completed forms
Manual and computerized screens and reports Samples of databases
Flowcharts and other system documentation
And more
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Sampling Techniques
Randomization a sampling technique
characterized by having no predeterminedpattern or plan for selecting sample data.
Stratification a systematic samplingtechnique that attempts to reduce the variance
of the estimates by spreading out the
samplingfor example, choosing documentsor records by formulaand by avoiding very
high or low estimates.
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Observation
Observation a fact-finding technique
wherein the systems analyst eitherparticipates in or watches a person perform
.
Advantages?
Disadvantages?
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Observation Guidelines Determine the who, what, where, when, why, and how of the
observation.
Obtain permission from appropriate supervisors or managers.
Inform those who will be observed of the purpose of the
.
Keep a low profile.
Take notes during or immediately following the observation.
Review observation notes with appropriate individuals.
Don't interrupt the individuals at work. Don't focus heavily on trivial activities.
Don't make assumptions.
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QuestionnairesQuestionnaire a special-purpose document that allows the analystto collect information and opinions from respondents.
Advantages?
Disadvantages?
-
respondent greater latitude in the answer. A question is asked, andthe respondent records the answer in the space provided after thequestion.
Fixed-format questionnaire a questionnaire containing questionsthat require selecting an answer from predefined availableresponses.
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Types of Fixed-Format Questions
Multiple-choice questions
Rating questions
Ranking questionsRankthefollowingtransactionsaccordingtotheamountoftimeyouspendprocessingthem.
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___%newcustomerorders
___%ordercancellations
___%ordermodifications
___%payments
Theimplementationofqualitydiscountswould
causeanincreaseincustomerorders.
Stronglyagree
Agree
NoopinionDisagree
StronglydisagreeIsthecurrentaccountsreceivable
reportthatyoureceiveuseful?
Yes
No
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Developing a Questionnaire1. Determine what facts and opinions must be
collected and from whom you should get them.2. Based on the facts and opinions sought,
determine whether free- or fixed-format
questions will produce the best answers.3. Write the questions.
4. Test the questions on a small sample of
respondents.5. Duplicate and distribute the questionnaire.
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Interviews
Interview - a fact-finding technique whereby
the systems analysts collect information from
individuals through face-to-face interaction.
Can be used to:
Thepersonalinterviewis
n acts
Verify facts
Clarify facts
Advantages?
Disadvantages?
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generallyrecognizedasthe
mostimportantandmostoften
usedfact-findingtechnique.
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Types of Interviews and QuestionsUnstructured interview an interview that is conducted with onlya general goal or subject in mind and with few, if any, specific
questions. The interviewer counts on the interviewee to provide aframework and direct the conversation.
specific set of questions to ask of the interviewee.
Open-ended question question that allows the interviewee torespond in any way that seems appropriate.
Closed-ended question a question that restricts answers to eitherspecific choices or short, direct responses.
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Procedure to Conduct an Interview
1.Select IntervieweesEnd users
Learn about individual prior to the interview
2.Prepare for the Interview
questions the interviewer will ask the interviewee.
3.Conduct the InterviewSummarize the problem
Offer an incentive for participation
4.Follow Up on the InterviewMemo that summarizes the interview
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Sample Interview Guide
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Discovery Prototyping
Discovery prototyping the act of building a
small-scale, representative or working modelof the users requirements in order to discover
.
Advantages?
Disadvantages?
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Joint Requirements Planning
Joint requirements planning (JRP) a process
whereby highly structured group meetings areconducted for the purpose of analyzing
.
JRP is a subset of a more comprehensive joint
application development or JAD technique that
encompasses the entire systems development
process.
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JRP Participants
Sponsor
Facilitator
Users and Managers
Scribes IT Staff
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Steps to Plan a JRP Session1. Selecting a location
Away from workplace when possible
Requires several rooms
Equipped with tables, chairs, whiteboard, overheadprojectors
Needed computer equipment
See Figure 6-4
2. Selecting the participants Each needs release from regular duties
3. Preparing the agenda Briefing documentation
Agenda distributed before each session
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Typical room layout for JRP session
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Guidelines for Conducting a JRP
Session Do not unreasonably deviate from the agenda
Stay on schedule
Ensure that the scribe is able to take notes
Avoid the use of technical jargon
Allow for ample breaks Encourage group consensus
Encourage user and management participation without
allowing individuals to dominate the session Make sure that attendees abide by the established
ground rules for the session
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Brainstorming Guidelines Isolate the appropriate people in a place that will be free from
distractions and interruptions.
Make sure everyone understands the purpose of the meeting.
Appoint one person to record ideas.
Remind ever one of brainstormin rules.
Within a specified time period, team members call out theirideas as quickly as they can think of them.
After the group has run out of ideas and all ideas have beenrecorded, then and only then should the ideas be analyzed
and evaluated. Refine, combine, and improve the ideas that were generated
earlier.
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Benefits of JRP JRP actively involves users and management in
the development project (encouraging themto take ownership in the project).
JRP reduces the amount of time re uired to
develop systems. When JRP incorporates prototyping as a
means for confirming requirements and
obtaining design approvals, the benefits ofprototyping are realized
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A Fact-Finding Strategy1. Learn from existing documents, forms, reports, and
files.
2. If appropriate, observe the system in action.
3. Given all the facts that already collected, design anddistribute questionnaires to clear up things that arent
fully understood.4. Conduct interviews (or group work sessions).
5. (Optional). Build discovery prototypes for anyfunctional requirements that are not understood or for
requirements that need to be validated.6. Follow up to verify facts.
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