Data Gathering Techniques 27 th February 2012

Data Gathering Techniques System requirements specify what the system must do or what property or quality the system must have Need to be able to gather system requirements – Functional Requirements – Non-functional Requirements

Functional Requirements: System requirements that specify what the system must do are frequently referred to as functional requirements Non-Functional Requirements: Specify properties or qualities of the system 3 Functional and Non Functional Requirements

More costly than projected Delivered later than promised Fail to meet users expectations Cost of maintenance may be too high Unreliable and prone to errors Negative impact on reputation of IT staff 4 Failure to correctly identify system requirements:

Once the system analyst understands the problems they can successfully define the system requirements They use fact-finding techniques to collect information about the system problems, requirements and preferences Fact-finding defines a formal process of using research, meetings, interviews and questionnaires etc. 5 Requirements Discovery

Document the draft requirements Analyse requirements – Identify missing reqs. – Conflicting reqs. – Infeasible reqs. – Overlapping reqs. – Ambiguous reqs. Formalize requirements – Produce requirements definition document 6 Documenting and Analysing Requirements

An analyst usually applies many techniques during a project leveraging advantages of each Analysts must take great care to ensure they conduct business in an ethical manner 7 Fact finding Techniques

Enables the analyst to get a good feel for the existing system Always gets the facts from existing documentation rather than from people Employ document and file sampling techniques 8 Existing Documentation and Forms

Site visits with companies who have experienced similar problems 9 Research and Site Visits

Analyst either observes or participates in activities to learn about the system Advantages: – Very reliable – Reduce the complexity of tasks – Inexpensive – Facilitates work measurements Disadvantages: – People may behave differently – Time period may not convey the complexity of the work – Inconvenient schedule – Task interruptions – Does not allow for analyst to see system exceptions – Work may be contrived due to presence of analyst 10 Observation of the Work Environment

Advantages: – Quick – Inexpensive – Maintain anonymity – Rapid analysis Disadvantages: – Number of respondents – Response rate – Inflexible – No body language – Lack of opportunity for clarification – Difficult to prepare 11 Questionnaires

Advantages: – Interviewees can actively contribute to the system – Opportunity for further probing – Adapt to interviewee – Observe non-verbal communication Disadvantages: – Time-consuming – Dependent on analysts interpersonal skills – Impractical 12 Interviews

Select interviewees Prepare Follow up on interview Listening Body language 13 Conducting Interviews

Advantages – Users can experiment with software – Assess the feasibility of system – Acts as training mechanism – Aids to build test plan – Minimise time spent on fact finding Disadvantages – Training may be required – Users may develop unrealistic expectations – May extend development schedule and cost 14 Discovery Prototyping

Highly structured group meetings are conducted for the purpose of analysing problems and defining problems Including: – Sponsor, facilitator, users/managers, scribe, IT staff – Benefits: – Involves users and managers – Reduces system development time – Design approvals based on prototyping 15 Joint Requirements Planning

Systems analyst needs an organised method for collecting fact. – Learn from existing documents – If appropriate observe system in action – Distribute questionnaire – Conduct interviews – Build discovery prototype (optional) – Follow-up –use appropriate fact-finding techniques to verify facts 16 Fact Finding Strategy