Lecture5v2.ppt

UKAI 2063 Accounting Information Systems II Lecture 5 Fact Finding Techniques  Lecture 5 Outline Requirements discovery & fact-finding techniques Interview, document review, observation, surveys, and questionnaires, sampling, and research...

UKAI 2063 Accounting Information Systems II Lecture 5 Fact Finding Techniques  Lecture 5 Outline Requirements discovery & fact-finding techniques Interview, document review, observation, surveys, and questionnaires, sampling, and research 5-2 Source: http://www.umsl.edu/~sauter/analysis/random_analysis_thoughts.ht 5-3 “Every project succeeds or fails on the quality of its requirements. They set the scope of all subsequent work and tell the project team what the users want. Without good requirements, projects fail, are late, come in over budget, or produce systems that are never used” (Alexander and Stevens, 2002). “Requirement issues should be fixed early, before committing to a design, because problems caused by poor requirements tend to be deeply embedded in the design and are difficult to remedy afterwards” (Alexander and Stevens, 2002). 5-4  Phase Description Systems analysis is the second of five phases in the systems development life cycle (SDLC) Will use requirements modeling, data and process modeling, and object modeling techniques to represent the new system Will consider various development strategies for the new system, and plan for the transition to systems design tasks 5-5  Systems Analysis Phase Overview The overall objective of the systems analysis phase is to understand the proposed project, ensure that it will support business requirements, and build a solid foundation for system development You use models and other documentation tools to visualize and describe the proposed system 5-6 Systems Analysis Phase Overview Systems Analysis Activities Requirements modeling Outputs Inputs Processes Performance Security 5-7  Systems Analysis Phase Overview Systems Analysis Activities Data and process modeling Object Modeling Development Strategies System requirements document 5-8  Systems Analysis Phase Overview Systems Analysis Skills Analytical skills Interpersonal skills Team-Oriented Methods and Techniques Joint application development (JAD) Rapid application development (RAD) Agile methods 5-9 What is a requirement? A requirement is a condition or capability that must be met or possessed by a system or system component to satisfy a contract, standard, specification, or other formally imposed documents. A well-formed requirement is a statement of system functionality (a capability) that must be met or possessed by a system to satisfy a customer’s need or to achieve a customer’s objective, and that is qualified by measurable conditions and bounded by constraints. 5 - 10 Types of requirements Functional requirements. Non-functional requirements. 5 - 11 Functional requirements A requirement that specifies an action that a system must be able to perform, without considering physical constraints; a requirement that specifies input/output behavior of a system. The important point to note is that: WHAT is wanted is specified, and not HOW it will be delivered. 5 - 12 Functional requirements - some examples If you are buying a vehicle for a business, your functional requirement might be: The vehicle should be able to take a load from a warehouse to a shop. Similarly for a computer system you define what the system is to do, e.g. The system should store all the details of a customer’s order. 5 - 13 Non-functional requirements A requirement that specifies system properties, such as environmental and implementation constraints, performance, platform dependencies, maintainability, extensibility, and reliability. These are the restrictions or constraints to be placed on the system and how to build it. Their purpose is to restrict the number of solutions that will meet a set of requirements. 5 - 14 Non-functional requirements - some examples The vehicle example, without any constraints, might result in solutions being offered for everything from a large truck to a sports car. To restrict the types of solutions you might include these constraints, e.g. It must take a load of at least one ton. The load area must be covered. The load area must have a height of at least 10 feet. 5 - 15 For the customer records example these might be: Information should be made available and be stored in a maximum of 3 seconds. The system should be available from 9am to 5 pm Monday to Friday. The system should be able to hold a 100,000 customer records initially. The system should be able to add 10,000 records a year for 10 years. A record should be fully available on the system for at least 7 years. 5 - 16 Categories of non-functional requirements Performance requirements: a requirement that specifies performance characteristics that a system or system component must possess. External interface requirements: a requirement that specifies hardware, software, or database elements with which a system or system component must interface or that sets forth constraints on formats, timing, or other factors caused by such an Source: interface. Parviainen, Tihinen and Solingen (2005 5 - 17 Design constraints: a requirement that affects or constrains the design of a system or system component, for example, language requirements, physical hardware requirements, software development standards, and software quality assurance standards. Quality attributes: a requirement that specifies the degree to which a system possesses attributes that affect quality, for example, correctness, reliability, maintainability, portability. Source: Parviainen, Tihinen and Solingen (2005 5 - 18 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. Once in production, the costs of maintaining and 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 tarnished because any failure, regardless of who is at fault, will be perceived as a mistake by the team. 5 - 19  Joint Application Development User Involvement Users have a vital stake in an information system and they should participate fully Successful systems must be user- oriented, and users need to be involved One popular strategy for user involvement is a JAD team approach 20 5 - 20  Joint Application Development JAD Participants and Roles 21 5 - 21  Joint Application Development JAD Advantages and Disadvantages More expensive and can be cumbersome if the group is too large relative to the size of the project Allows key users to participate effectively When properly used, JAD can result in a more accurate statement of system requirements, a better understanding of common goals, and a stronger commitment to the success of the new system 22 5 - 22  Rapid Application Development RAD Phases and Activities 23 5 - 23  Rapid Application Development RAD Objectives To cut development time and expense by involving the users in every phase of systems development Successful RAD team must have IT resources, skills, and management support Helps a development team design a system that requires a highly interactive or complex user interface 24 5 - 24  Rapid Application Development RAD Advantages and Disadvantages Systems can be developed more quickly with significant cost savings RAD stresses the mechanics of the system itself and does not emphasize the company’s strategic business needs Might allow less time to develop quality, consistency, and design standards 25 5 - 25  Agile Methods Attempt to develop a system incrementally Agilian modeling toolset includes support for many modeling tools Some agile developers prefer not to use CASE tools at all, and rely instead on whiteboard displays and arrangements of movable sticky notes 26 5 - 26  Agile Methods Agile Method Advantages and Disadvantages Are very flexible and efficient in dealing with change Frequent deliverables constantly validate the project and reduce risk Team members need a high level of technical and interpersonal skills May be subject to significant change in scope 27 5 - 27  Modeling Tools and Techniques CASE Tools Functional Decomposition Diagrams Data Flow Diagrams Unified Modeling Language 28 5 - 28  System Requirements Checklist Outputs 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 29 5 - 29  System Requirements Checklist Inputs Manufacturing employees must swipe their ID cards into online data collection terminals that record labor costs and calculate production efficiency The department head must enter overtime hours on a separate screen 30 5 - 30  System Requirements Checklist Processes The student 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 31 5 - 31  System Requirements Checklist Performance The system must support 25 users online simultaneously Response time must not exceed four seconds 32 5 - 32  System Requirements Checklist Controls 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 33 5 - 33  Future Growth, Costs, and Benefits Scalability 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 34 5 - 34  Future Growth, Costs, and Benefits Total Cost of Ownership – Total cost of ownership (TCO) is especially important if the development team is evaluating several alternatives – One problem is that cost estimates tend to understate indirect costs – Rapid Economic Justification (REJ) 35 5 - 35  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 36 5 - 36  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 37 5 - 37  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 38 5 - 38  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 Ask the interviewee to have samples available 39 5 - 39  Interviews Step 5: Conduct the Interview Develop a specific plan for the meeting Begin by introducing yourself, describing the project, and explaining your interview objectives Engaged listening Allow the person enough time to think about the question After an interview, you should summarize the session and seek a confirmation 40 5 - 40  Interviews Step 6: Document the Interview – Note taking should be kept to a minimum – After conducting the interview, you must record the information quickly – After the interview, send memo to the interviewee expressing your appreciation – 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 41 5 - 41  Interviews Step 7: Evaluate the Interview In addition to recording the facts obtained in an interview, try to identify any possible biases Unsuccessful Interviews No matter how well you prepare for interviews, some are not successful 42 5 - 42  Other Fact-Finding Techniques Document Review Observation – Seeing the system in action gives you additional perspective and a better understanding of the system procedures – Plan your observations in advance – Hawthorne Effect 43 5 - 43 Other Fact-Finding Techniques Questionnaires and 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 44 5 - 44  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 45 5 - 45  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 46 5 - 46  Other Fact-Finding Techniques Interviews versus Questionnaires Interview is more familiar and personal Questionnaire gives many people the opportunity to provide input and suggestions Brainstorming Structured brainstorming Unstructured brainstorming 47 5 - 47 A fact-finding strategy Learn all you can from existing documents, forms, reports, and files. Ifappropriate, observe the system in action. Given all the facts that you've already collected, design and distribute questionnaires to clear up things you don't fully understand. 5 - 48  Documentation The Need for Recording the Facts Record information as soon as you obtain it Use the simplest recording method Record your findings in such a way that they can be understood by someone else Organize your documentation so related material is located easily 49 5 - 49 Documentation Software Tools CASE Tools Productivity Software Graphics modeling software Personal information managers Wireless communication devices 50 5 - 50  Preview of Logical Modeling At the conclusion of requirements modeling, systems developers should have a clear understanding of business processes and system requirements The next step is to construct a logical model of the system IT professionals have differing views about systems development methodologies, and no universally accepted approach exists 51 5 - 51  Acknowledgements This PowerPoint presentation contains materials complied from various sources. Credits are hereby given to their respective owners. Please refer to the reading list for details. Reminder The lecture slides serve only as a quick learning guide. Students are required to refer to the main textbook for detailed elaboration. 5 - 52