Chapter 3 Requirements Analysis PDF

Systems Analysis and Design Roberta Roth, Alan Dennis, and Barbara Haley Wixom  Analysis refers to breaking a whole into its parts with the intent of understanding the parts’ nature, functions, and interrelationships.  The planning phase deliverables are the key inputs into the analys...

Systems Analysis and Design Roberta Roth, Alan Dennis, and Barbara Haley Wixom  Analysis refers to breaking a whole into its parts with the intent of understanding the parts’ nature, functions, and interrelationships.  The planning phase deliverables are the key inputs into the analysis phase. The basic process of analysis involves three steps: - Understand the existing situation (the as-is system) -Identify improvements - Define the requirement for the new system (the to-be system).  The final deliverables of the analysis phase is the system proposal.  The system proposal is presented to the approval committee in the form of a system walk-through to explain the system in moderate detail.  The deliverables from the analysis phase are the first step in the design of the new system. Requirements determination is performed to transform the system request’s high-level statement of business requirements into a more detailed, precise list of what the new system must do to provide the needed value to the business.  A requirement is a statement of what the system must do or what characteristics it needs to have.  Requirements describe - what the business needs (business requirements) - what the users need to do (user requirements) - what the software should do (functional requirements) - characteristics the system should have (non- functional requirements), and - how the system should be built (system requirements)  Functional requirements  Nonfunctional requirements  Both business and IT perspectives are needed to determine requirements during the analysis phase.  The most effective approach is to have both businesspeople and analysts working together to determine requirements.  The analyst must also consider how best to elicit the requirements from the stakeholders.  The process of determining requirements continues throughout the analysis phase, and the requirements definition evolves over time. Requirements Elicitation in Practice  The analyst should recognize that important side effects of the process of determining requirements include building political support for the project and establishing trust between the project team and the users.  The analyst should carefully determine who is included in the process of determining requirements.  The most commonly used requirements elicitation technique  Basic steps: – Selecting Interviewees – Designing Interview Questions – Preparing for the Interview – Conducting the Interview – Post-Interview Follow-up  Inter view schedule  Unstructured interview –for a broad and roughly defined set of information  Structured interview – for very specific information  Top-down vs. bottom-up interview  Prepare a general interview plan  Confirm areas of knowledge  Set priorities in case of time shortage  Prepare the interviewee – Schedule – Inform of reason for interview – Inform of areas of discussion   Appear to be professional and unbiased.  Record all information.  Be sure you understand the CONDUCTINGTHE issues that are discussed. INTERVIEW  Separate facts from opinions.  Give interviewee time to ask questions, and brief explain what will happen next.   Afterthe interview, the analysts needs to prepare an interview report.  The report includes POST-INTERVIEW interview notes. FOLLOW-UP  The report is sent to interviewee with a request to read it and inform the analyst of clarification and updates.  JAD is an information gathering technique that allows the project team, users, and management to work together to identify requirements for the system.  It can reduce scope creep by 50%,  JAD is a structure process in which 10 to 20 users meet under the direction of a facilitator skilled in JAD techniques.  Selecting JAD participants in the same basic way as selecting interview participants.  Facilitator – Expert in JAD and e-JAD techniques – In many cases, the JAD facilitator is a consultant external to the organization. JAD sessions can run from a half day to several weeks depending upon the size and scope of the project. JAD success depends upon a careful plan.  Most JAD sessions are designed to collect specific information from users.  It is important to prepare the analyst and participants for the JAD session.  Most JAD sessions follow formal agenda and ground rules.  The JAD facilitator performs three key functions: – Keep session on track, following the agenda. – Help the group understand the technical terms and jargon. – Record group’s input on a public display area.  The facilitator must remain neutral at all time and help the group through the process.  Postsession report is prepared and circulated among session attendees  The report should be completed approximately a week to two after the JAD session A questionnaire is a set of written questions for obtaining information from individuals.  Selecting participants - using a sample of people who are representative of the entire group.  Designing the questionnaire – following good practice guidelines.  Administering the questionnaire – improving the response rates.  Questionnaire follow-up – developing a report.  Good questionnaire design  Document analysis is used to understand the as- is system.  Forms, reports, policy manuals, organization charts describe the formal system that the organization uses.  The “real” or informal system differs from the formal one, and reveals what needs to be changed.  The indication that system needs to be changed is when users create new forms or make  Observation – the act of watching processes being performed.  It is a powerful tool to gain insight into the as-is system, and to check the validity of information gathered from other sources.  Nonetheless, people tend to be extremely careful in their behaviors when they are being watched.  Type of information  Depth of information  Breadth of information  Integration of information  User involvement  Cost  Comparison of Requirements Elicitation Techniques  Asking users to identify problems and solutions  Improvements from problem analysis tend to be small and incremental  This type of improvements often is very effective at improving a system’s efficiency or ease of use; however, it provides minor improvements in business value.  Root cause analysis focuses on problems first rather than solutions.  Duration analysis requires a detailed examination of amount of time it takes to perform each process in the as-is system.  Compare the total time to complete basic steps and the total time for the overall process – a significant difference indicates that the process is badly fragmented.  Potential solutions: – Process integration – Parallelization  Activity-based costing examines the cost of each major process or step in a business process.  Both direct and indirect costs are considered.  The analysts identify most costly steps and focus improvement efforts on them.  Benchmarking refers to studying how other organizations perform a business process.  Informal benchmarking is common for “customer-facing” processes.  The analysts visit other organizations as customers to watch how the business process is performed.  Outcome analysis focuses on understanding fundamental outcomes that provide value to customers.  Think what the organization could enable the customer to do  Technology analysis involves two steps: 1. The analysts and managers list important and interesting technologies. 2. Then, the group identifies how each and every technology might be applied to the business and how the business would benefit.  The analysts and managers work together to identify  how the organization could eliminate each and every activity in the business process,  how the function could operate without it, and  what effects are likely to occur.  Each of the requirement analysis strategies has its own purpose.  No one strategy is inherently better that the others.  The requirement analysis strategy should be chosen to fit the nature of the project.  Analysis focuses on capturing the business requirements for the system  Requirement Determination is the part of analysis in which the project team turns the business requirements stated in the system request into a precise list of requirements.  Five Requirements Elicitation Techniques can be used to elicit business requirements.  Requirements Analysis Strategies are useful for analysts to help the business users think critically about the new system requirements. Performance Task: Develop a questionnaire that will help gather information regarding processes at a popular restaurant or the college cafeteria (e.g., ordering, customer service). Give the questionnaire to 10–15 students, analyze the responses, and write a brief report that describes the results.