Software Tools

C H A P T E R 14

• Be able to define the terms system, analysis, and design

• A systems analyst knows that people are uneasy about having a stranger pry into their job situations and that they may be nervous about computers.
• The systems analyst helps people address change.

• A system is an organized set of related components established to accomplish a certain task. A computer system is a system that has a computer as one of its components.
• Systems analysis is the process of studying an existing system to determine how it works and how it meets user needs, laying the groundwork for improvements to the system..
• A client is the person or organization contracting to have the work done.
• Users are people who have contact with the system, usually employees and customers.
• Systems design is the process of developing a plan for an improved system, based on the results of the systems analysis.
• The systems analyst normally performs both analysis and design. In some installations a person who is mostly a programmer may also do some systems analysis and have the title programmer/analyst.
• Systems analysis and design require an impetus—motivation—for change and the related authority for change. The motivation can be either internal (management decision, for example) or external (customer complaints, for example). The authority for systems analysis and design comes from higher management.

• The systems analyst fills the role of change agent, the catalyst or persuader who overcomes the natural inertia and reluctance to change within an organization.
• The key to a systems analyst’s success is user involvement, the active participation of the client organization’s people in the development of the new system.

• The systems analyst has three principal functions:

• The systems development life cycle (SDLC) has five phases:

• The preliminary investigation—often called the feasibility study, or system survey—is the initial investigation, a brief study of the problem.

• The analyst’s initial aim is to define the problem.
• The analyst and the users must agree on the nature of the problem, designate a limited scope, and determine the objectives of the project.

• The analyst must determine the true nature of the problem.

• The analyst and user must agree on the scope of the project: what the new or revised system is supposed to do—and not do.

• Express user needs—that is, what the user thinks the system should be able to do—as objectives.

• The preliminary investigation should wrap up with a report telling management what you found and listing your recommendations.
• At this point, management can (1) drop the matter; (2) fix the problem immediately, if it is simple; or (3) authorize you to go on to the next phase for a closer look.

• The purpose of systems analysis is to understand the exiting system. A related goal is to establish the system requirements.

• Data gathering is expensive and requires a lot of legwork and time.
• Commonly used sources are written documents, interviews, questionnaires, observation, and sampling.

• Written documents include procedures manuals, reports, forms, and other material bearing on the problem.

• Interviewers can ask open-ended questions and, in addition to answers, can observe the non-verbal responses of the interviewee.
• Interviews have the added advantage of getting to know the user.
• The major disadvantage of interviews is that they are time-consuming and therefore expensive.
• There are two types of interviews—structured and unstructured.
• A structured interview includes only questions that have been planned and written out in advance.
• The unstructured interview includes questions prepared in advance, but the interviewer is willing to vary from the line of questioning and pursue other subjects if they seem appropriate.

• Questionnaires can be used to get information from large groups of people.
• Advantages of questionnaires are anonymity and evidence of trends.
• Disadvantages of questionnaires are unreturned questionnaires and biased answers.

• Observation involves the analyst as observer.
• One form of observation is participant observation, in which the analyst temporarily joins the activities of the group.

• Sampling is a technique of gathering only a certain percentage of data from a high volume.
• Sampling is typically used for collecting data about quantities, costs, time periods, and other factors relevant to the system.

• Once you have all the data gathered, there are a variety of tools—charts and diagrams—used to analyze data.
• Two typical tools are data flow diagrams and decision tables.

• A data flow diagram (DFD) is a sort of road map that graphically shows the flow of data through a system.
• The elements of a data flow diagram are processes, files, sources and sinks, and vectors.
• Processes are the actions taken on the data—comparing, checking, stamping, authorizing, filing, and so forth.
• A file is a repository of data—a tape or disk file, a set of papers in a file cabinet, or even mail in an in-basket or blank envelopes in a supply bin.
• A source is a data origin outside the organization; an example is a payment sent to a department store by a charge customer (who is the source of data).
• A sink is the destination for data going outside the organization; an example is the bank that receives money from the accounts receivable organization.
• Vectors are simply arrows—lines with directional notation.

• A decision table, also called a decision logic table, is a standard table of the logical decisions that must be made regarding potential conditions in a given system.
• Decision tables are useful in cases that involve a series of related decisions.

• A by-product of systems analysis is the system requirements, a detailed list of the things the system must be able to do.
• The design of the new system will be based on the system requirements, so they must be accurate.
• Another reason that the requirements must be accurate is that the system will be evaluated in terms of how well the requirements were met.

• When you finish the systems analysis phase, you present a comprehensive report to management that summarizes the problems found and describes the requirements for the new system.
• The report includes recommendations on what course to take next.

• The systems design phase is the phase in which the analyst plans the new system.
• There are two subphases: preliminary design, in which the analyst establishes the new system concept, followed by detail design, in which the analyst determines exact design specifications.

• The first task of preliminary design is to review the system requirements, then to consider some of the major aspects of a system.

• A client can adjust ways of doing business to match purchased package software or, more expensively, customize, or alter, the packaged software to meet the client’s special needs.

• Each candidate meets the user’s requirements but with variations in features and costs. The chosen candidate is usually the one that best meets the user’s current needs and is flexible enough to meet future needs.

• Considered from a systems viewpoint, a prototype is a limited working system—or subset of a system—that is developed quickly, sometimes in just a few days.

• Once users have accepted a design proposal, it is time to develop detailed design specifications.
• This is a time-consuming part of the project in which every facet of the system is considered in detail.
• Normally, in the detail design phase, parts of the system are considered in this order:

• Before anything can be planned in detail, the analyst must know exactly what the user wants the system to produce: the output.

Input Requirements

• Once the desired output is determined, next consider what kind of input is required to produce it.

• Consider how the files in your computer system will be organized: sequentially, directly, or by some other method.

Systems Processing

• The analyst must show the flow of data in the new system.

Systems Controls and Backup

• To make sure data is input, processed, and output correctly and to prevent fraud and tampering with the computer system, the analyst must institute appropriate controls.

• The documentation, usually referred to as the detail design specifications, is an outgrowth of the preliminary design document. The report is also probably large and detailed. A presentation may accompany this report.

• During this phase, the system is actually developed. As a systems analyst, you must prepare a schedule to monitor the principal activities in systems development—programming and testing.

• A Gantt chart is a bar chart commonly used to depict schedule deadlines and milestones. The chart shows the work to be accomplished over a given period.

• Before programming begins, the analyst prepares detail design specifications.

• Programmers perform unit testing, in which they individually test their own programs, using test data.
• System testing follows, which determines whether all program units work together satisfactorily.
• Finally, volume testing uses real data in large amounts.
• Documentation, as in every phase, is also required. In this phase, documentation describes the program logic and detailed data formats.

• Although implementation is the final phase, a good deal of effort is still required, including training, equipment conversion, file conversion, system conversion, auditing, evaluation, and maintenance.

• An important tool in training is the user’s manual, a document prepared to aid users not familiar with the computer system.
• Users must receive hands-on training to learn to use the system.

• Equipment considerations vary from almost none to installation of large computer systems and all the peripheral equipment.
• This may involve large amounts of time and attention, including site preparation, electrical requirements, and other factors of space, accessibility, and cleanliness.

• The existing files must be prepared in such a way that they are accessible to computer systems.
• Existing machine-accessible files need to be updated or converted to the format needed for the new system.
• It is not unusual for this process to take a long time.

• There are four ways of handling system conversion:

• Security is an important issue. An audit trail allows you to trace output back to the source data.
• Modern auditors use their own computers programs to monitor applications programs and data.

• Evaluating the new system can be done by the systems analyst and someone from the client organization.
• This is usually done against preset criteria, probably the system requirements.
• Some clients prefer to bring in an independent evaluating team.

• Maintenance is an ongoing activity, one that lasts the lifetime of the system.

• Maintenance tasks include making revisions and additions to the computer system.

• Many novice systems analysts think there is a formula for their work; however, they usually learn that their formulas are merely guidelines.
• Each system is unique, so there can be no one way that fits every project.