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CIS 2303 LO2 Part 3
This document discusses requirements modeling during the analysis phase of the systems development life cycle. It covers the importance of requirements, identifying requirements through various fact-finding techniques like interviews and questionnaires, and categorizing requirements into functional and technical categories like inputs, outputs, processes, performance, and controls. Key points covered include understanding user needs, determining requirements through open-ended questions in interviews, and using sampling approaches to ensure representations of the overall population.
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CIS 2303 LO2 Part 3
- 1. Systems Analysis andDesign CIS 2303 Part 3 An extension to Learning Outcome 2: SDLC: Analysis Phase (Requirement Modeling) – Ch4
- 2. Lecture Objectives 1. Understandimportance of requirements 2. Identify Requirements 3. Fact-finding techniques 2
- 3. Importance of Systems Requirement Systems Requirements is a feature that must be included in order for the system to be acceptable to users. Two categories: 1) Functional requirements describe activities or processes the system must perform (e.g., calculate payroll taxes). 2) Technical requirements describe an operating environment or performance objective (e.g., must run with UNIX or must have one-half second response time). 3
- 4. Identify System Requirements Systems Analysis Activities ◦ Requirements modeling has the following categories: Outputs Inputs Processes Performance Controls 4
- 5. System Requirements Checklist Outputs Examples: -The Web site must report online volume statistics every four hours, and hourly during peak periods - The inventory system must produce a daily report showing the part number, description, quantity on hand, quantity allocated, quantity available, and unit cost of all sorted by part number 5
- 6. System Requirements Checklist Inputs Examples: - Thedepartment head must enter overtime hours on a separate screen - Student grades must be entered on machine-scannable forms prepared by the instructor. - Each input form must include date, time, product code, customer number, and quantity 6
- 7. System Requirements Checklist Processes Examples: - Thestudent records system must calculate the GPA at the end of each semester - As the final step in year-end processing, the payroll system must update employee salaries, bonuses, and benefits and produce tax data required by the IRS 7
- 8. System Requirements Checklist Performance Examples: -Thesystem must support 25 users online simultaneously - Response time must not exceed four seconds 8
- 9. System Requirements Checklist Controls Examples: -The system must provide logon security at the operating system level and at the application level - An employee record must be added, changed, or deleted only by a member of the human resources department 9
- 10. Future Growth, Costs,and Benefits Scalability Why?: ◦ A scalable system offers a better return on the initial investment ◦ To evaluate scalability, you need information about projected future volume for all outputs, inputs, and processes 10
- 11. 11 In-Class Exercise Studythe DWC “Portal System” and give one example to each of the following: ◦ Inputs ◦ Outputs ◦ Processes ◦ Performance ◦ Control
- 12. Fact-Finding Fact-Finding Overview ◦First, you must identify the information you need ◦ Develop a fact-finding plan Who, What, Where, When, How, and Why? ◦ Difference between asking what is being done and what could or should be done 12
- 13. Interviews Step 1:Determine the People to Interview ◦ Informal structures Step 2: Establish Objectives for the Interview ◦ Determine the general areas to be discussed ◦ List the facts you want to gather 13
- 14. Interviews Step 3:Develop Interview Questions ◦ Creating a standard list of interview questions helps to keep you on track and avoid unnecessary tangents ◦ Avoid leading questions ◦ Open-ended questions ◦ Closed-ended questions ◦ Range-of-response questions 14
- 15. Interviews Step 4:Prepare for the Interview ◦ Careful preparation is essential because an interview is an important meeting and not just a casual chat ◦ Limit the interview to no more than one hour ◦ Send a list of topics Step 5: Conduct the Interview ◦ Develop a specific plan for the meeting 15
- 16. Interviews • Step 6:Document the Interview –Note taking should be kept to a minimum –Note date, time, location, purpose of the interview, and the main points you discussed so the interviewee has a written summary and can offer additions or corrections Step 7: Evaluate the Interview ◦ In addition to recording the facts obtained in an interview, try to identify any possible biases 16
- 17. Other Fact-Finding Techniques • DocumentReview • Observation – Seeing the system in action gives you additional perspective and a better understanding of the system procedures 17
- 18. Other Fact-Finding Techniques Questionnairesand Surveys ◦ When designing a questionnaire, the most important rule of all is to make sure that your questions collect the right data in a form that you can use to further your fact-finding ◦ Fill-in form 18
- 19. Other Fact-Finding Techniques Sampling ◦Systematic sample ◦ Stratified sample ◦ Random sample ◦ Main objective of a sample is to ensure that it represents the overall population accurately 19
- 20. Other Fact-Finding Techniques Research ◦Can include the Internet, IT magazines, and books to obtain background information, technical material, and news about industry trends and developments ◦ Site visit 20
- 21. Other Fact-Finding Techniques Interviewsversus Questionnaires ◦ Interview is more familiar and personal ◦ Questionnaire gives many people the opportunity to provide input and suggestions ◦ Brainstorming 21
- 22. Review Questions: Whatare the five questions typically used in fact-finding? What additional question can be asked during this process? refer to (Page 157) What is a systems requirement, and how are systems requirements classified? refer to (Page 153) What are three types of sampling, and why would you use them? refer to (Page 167-168) 22
Editor's Notes
- #6 Outputs: Refer to electronic or printed information produced by the system (Ch.4 - page 142)
- #7 Inputs: Refer to necessary data that enters the system, either manually or in an automated manner (Ch.4 - page 142)
- #8 Processes: Refer to logical rules that are applied to transform the data into meaningful information.(Ch.4 - page 142)
- #9 Performatnce: Refer to system characteristics such as speed, volume, capacity, availability, and reliability. (Ch.4 – p 142)
- #11 Scalability: Refer to system availability to handle increased business volume and transactions in the future. Because it will have a longer useful life. (Ch.4 - page 155)
- #15 Leading questions that suggest or favor a particular reply. For example, rather than asking, “What advantages do you see in the proposed system?” you might ask, “Do you see any advantages in the proposed system?”OPEN-ENDED QUESTIONS encourage spontaneous and unstructured responses. Such questions are useful when you want to understand a larger process or draw out the interviewee’s opinions, attitudes, or suggestions. Hereare some examples of open-ended questions: What are users saying about the newsystem? How is this task performed? Why do you perform the task that way? Howare the checks reconciled? CLOSED-ENDED QUESTIONS: limit or restrict the response. You use closed-ended questions when you want information that is more specific or when you need to verify facts. Examples of closed-ended questions include the following:How many personal computers do you have in this department? Do you review the reports before they are sent out? How many hours of training does a clerk receive? How many customers ordered products from the Web site last month?RANGE-OF-RESPONSE QUESTIONS are closed-ended questions that ask the person to evaluate something by providing limited answers to specific responses or on a numeric scale. This method makes it easier to tabulate the answers and interpret the results. Range-of-response questions might include these: On a scale of 1 to 10, with 1 the lowest and 10 the highest, how effective was your training? How would you rate the severity of the problem: low, medium,or high? Is the system shutdown something that occurs never, sometimes, often, usually, or always?(Ch4. Pg. 160)
- #19 A questionnaire, also called a survey, is a document containing a number of standard questions that can be sent to many individuals. Questionnaires can be used to obtain information about a wide range of topics,including workloads, reports received, volumes of transactions handled, job duties,difficulties, and opinions of how the job could be performed better or more efficiently
- #20 (Ch4 – Pg. 167)Suppose you have a list of 200 customers who complained about errors in their statements,and you want to review a representative sample of 20 customers. Systematic sample would select every tenth customer for review. If you want to ensure that the sampleStratified sample ensures sample is balanced geographically, to select five customers from each of four zip codes. Another example of stratified sampling is to select a certain percentage of transactions from each zip code, rather than a fixed number.Random sample selects any 20 customers.
- #22 brainstorming, which refers to a small group discussion of a specific problem, opportunity, or issue. This techniqueencourages new ideas, allows team participation, and enables participants to build on each other’s inputs and thoughts