15: PTI Assignment 14

PTI Assignment 14: Chapter Review (Chapter 12) of textbook Discovering Computers

Lecturer: Mr. Tri Djoko Wahjono, Ir, M.Sc.

By: Veronica Ong (1701317660) of class 01PCT 

Task: Chapter Review of Chapter 12 from the Textbook Discovering Computers.

1. What is system development, and what are the system development phases?

As a computer user in a business, you someday may participate in the modification of an existing system or the development of a new system. Thus, it is important that you understand system development. System development is a set of activities used to build an information system. Some system development activities may be performed concurrently. Others are performed sequentially. Depending on the type and complexity of the information system, the length of each activity varies from one system to the next. In some cases, some activities are skipped entirely. System development activities often are grouped into larger categories called phases. This collection of phases sometimes is called the system development life cycle (SDLC).
Many SDLCs contain five phases: planning, analysis, design, implementation, operation, support, and security. Each phase of system development consists of a series of activities, and the phases form a loop. The loop forms when the operation, support, and security phase points to the planning phase. This connection occurs when the information system requires changing. A variety of situations can lead to a change in the information system. For example, users may want information in a different format, or an unauthorized user may have gained access to the information system. When change occurs or is required, the planning phase for a new or modified system begins and the SDLC starts again. In theory, the five system development phases often appear sequentially. In reality, activities within adjacent phases often interact with one another – making system development a dynamic iterative process. In the planning phase, there are 4 activities to be done, they are, review project requests, prioritize project requests, allocate resources, and form project development team. In the analysis phase, there are 2 activities to be done, which are conduct preliminary investigation, and perform detailed analysis activities (study current system, determine user requirements, recommend solutions). In the design phase, we acquire hardware and software if necessary, and we develop details of system. In the implementation phase, there are 4 activities, develop programs if necessary, install and test new system, train users, and convert to new system. In the operation, support, and security phase, there are 3 activities, which are perform maintenance activities, monitor system performance, and assess system security.

2. What are guidelines for system development?

System development should follow three general guidelines: group activities into phases, involve the users, and define standards.

1. Group activities or tasks into phases: Many SDLCs contain the same phases shown in Figure 12-1. Others have more or fewer phases. Regardless, all SDLCs have similar activities. For example, Figure 12-1 shows the ‘Develop programs’ and the ‘Install and test new system’ activities in the Implementation phase. Some SDLCs separate these activities in an additional phase called Construction and Testing. Other differences among SDLCs are the terminology they use, the order of their activities, and the level of detail within each phase.

2. Involve users: Users include anyone for whom the system is being built. Customers, employees, students, data entry clerks, accountants, sales managers, and owners all are examples of users. You, as a user, might interact with an information system at your bank, library, grocery store, fitness center, work, and school. The system development team members must remember they ultimately deliver the system to the user. If the system is to be successful, the user must be included in system development. Users are more apt to accept a new system if they contribute to its design.

3. Define standards: Standards are sets of rules and procedures an organization expects employees to accept and follow. Standards help people working on the same project produce consistent results. For example, one programmer might refer to a product number in a database as a product ID. Others may call it a product identification number, product code, and so on. If standards are defined, then everyone involved uses the same terms, such as product number. Standards often are implemented by using a data dictionary.

3. What are project management, feasibility assessment, documentation, and data and information gathering techniques important?

Project management is the process of planning, scheduling, and then controlling the activities during system development. The goal of project management is to deliver an acceptable system to the user in an agreed-upon time frame, while maintaining costs. In smaller organizations or projects, one person manages the entire project. For larger projects, the project management activities often are separated between a project manager and a project leader. In this case, the project leader manages and controls the budget and schedule of the project, and the project manager controls the activities during system development. Project leaders and/or project managers are part of the project team. If the systems analyst is not the project manager, he or she works closely with the project manager. Some organizations use extreme project management to speed development time. Extreme project management is a team-driven project management approach, in which a project leader is more of a participant and facilitator than a manager during the project. To plan and schedule a project effectively, the project leader identifies the following elements:

• Goal, objectives, and expectations of the project, collectively called the scope

• Required activities

• Time estimates for each activity

• Cost estimates for each activity

• Order of activities

• Activities that can take place at the same time

Feasibility is a measure of how suitable the development of a system will be to the organization. A project that is feasible at one point during system development might become infeasible at a later point. Thus, systems analysts frequently reevaluate feasibility during the system development project. A systems analyst typically uses at least four tests to evaluate feasibility of a project: operational feasibility, schedule feasibility, technical feasibility, and economic feasibility.

• Operational feasibility measures how well the proposed information system will work. Will the users like the new system? Will they use it? Will it meet their requirements? Will it cause any changes in their work environment? Is it secure?

• Schedule feasibility measures whether the established deadlines for the project are reasonable. If a deadline is not reasonable, the project leader might make a new schedule. If a deadline cannot be extended, then the scope of the project might be reduced to meet a mandatory deadline.

• Technical feasibility measures whether the organization has or can obtain the hardware, software, and people needed to deliver and then support the proposed information system. For most information system projects, hardware, software, and people typically are available to support an information system. The challenge is obtaining funds to pay for these resources. Economic feasibility addresses funding.

• Economic feasibility, also called cost/benefit feasibility, measures whether the lifetime benefits of the proposed information system will be greater than its lifetime costs. A systems analyst often consults the advice of a business analyst, who uses many financial techniques, such as return on investment (ROI) and payback analysis, to perform the cost/benefit analysis.

During system development, project team members produce much documentation. Documentation is the collection and summarization of data and information. It includes reports, diagrams, programs, or any other deliverables generated during system development. A project notebook contains all documentation for a single project. The project notebook might be a simple three-ring binder. Many organizations, however, have software that systems analysts use to create an automated project notebook. Users and IT professionals refer to existing documentation when working with and modifying current systems. It is important that all documentation be well written, thorough, consistent, and understandable. The final information system should be reflected accurately and completelyin documentation developed throughout the development project. Maintaining up-to-date documentation should be an ongoing part of system development. Too often, project team members put off documentation until the end because it is time-consuming, but these practices typically result in lower quality documentation.

During system development, members of the project team gather data and information. They need accurate and timely data and information for many reasons. They must keep a project on schedule, evaluate feasibility, and be sure the system meets requirements. Systems analysts and other IT professionals use several techniques to gather data and information. They review documen tation, observe, survey, interview, conduct joint-application design sessions, and research.

• Review Documentation — By reviewing documentation such as an organization chart, memos, and meeting minutes, systems analysts learn about the history of a project. Documentation also provides information about the organization such as its operations, weaknesses, and strengths.

• Observe — Observing people helps systems analysts understand exactly how they per form a task. Likewise, observing a machine allows you to see how it works.

• Survey — To obtain data and information from a large number of people, systems analysts distribute surveys.

• Interview — The interview is the most important data and information gathering technique for the systems analyst. It allows the systems analyst to clarify responses and probe during face-to-face feedback.

• JAD Sessions — Instead of a single one-on-one interview, analysts often use joint-application design sessions to gather data and information. Joint-application design (JAD) sessions, or focus groups, are a series of lengthy, structured, group meetings in which users and IT professionals work together to design or develop an application.

• Research — Newspapers, computer magazines, reference books, trade shows, the Web, vendors, and consultants are excellent sources of information. These sources can provide the systems analyst with information such as the latest hardware and software products and explanations of new processes and procedures. In addition, systems analysts often collect Web site statistics such as the number of visitors, most visited Web pages, etc., and evaluate these statistics as part of their research.

4. What activities are performed in the planning phase?

The planning phase for a project begins when the steering committee receives a project request. As mentioned earlier in this chapter, the steering committee is a decision making body for an organization. This committee usually consists of five to nine people. It typically includes a mix of vice presidents, managers, non management users, and IT personnel. During the planning phase, four major activities are performed: (1) review and approve the project requests; (2) prioritize the project requests; (3) allocate resources such as money, people, and equipment to approved projects; and (4) form a project development team for each approved project. The projects that receive the highest priority are those mandated by management or some other governing body. These requests are given immediate attention. The steering committee evaluates the remaining project requests based on their value to the organization. The steering committee approves some projects and rejects others. Of the approved projects, it is likely that only a few will begin system development immediately. Others will have to wait for additional funds or resources to become available.

5. What is the purpose of activities performed in the analysis phase?

The analysis phase consists of two major activities: (1) conduct a preliminary investigation and (2) perform detailed analysis. The main purpose of the preliminary investigation, sometimes called the feasibility study, is to determine the exact nature of the problem or improvement and decide whether it is worth pursuing. Should the organization continue to assign resources to this project? To answer this question, the systems analyst conducts a general study of the project. Then, the systems analyst presents his or her findings in a report. Figure 12-6 shows a sample feasibility report, also sometimes known as the feasibility study. In this phase, the systems analyst defines the problem or improvement accurately. The actual problem may be different from the one suggested in the project request. The first activity in the preliminary investigation is to interview the user who submitted the project request. Depending on the nature of the request, project team members may interview other users, too. In the case of the school, members of the team might interview the controller for data entry and quality control costs. They also might interview one or two registration clerks, quality control clerks, instructors, and students. In addition to interviewing, members of the project team may use other data gathering techniques, such as reviewing existing documentation. The time spent on this phase of system development is quite short when compared with the remainder of the project. Often, the preliminary investigation is completed in just a few days. Detailed analysis involves three major activities: (1) study how the current system works; (2) determine the users’ wants, needs, and requirements; and (3) recommend a solution. Detailed analysis sometimes is called logical design because the systems analysts develop the proposed solution without regard to any specific hardware or software. That is, they make no attempt to identify the procedures that should be automated and those that should be manual. During these activities, systems analysts use all of the data and information gathering techniques. They review documentation, observe employees and machines, distribute surveys, interview employees, conduct JAD sessions, and research. An important benefit from these activities is that they build valuable relationships among the systems analysts and users. While studying the current system and identifying user requirements, the systems analyst collects a great deal of data and information. A major task for the systems analyst is to document these findings in a way that can be understood by everyone. Both users and IT professionals refer to this documentation. Most systems analysts use either a process modeling or object modeling approach to analysis and design. The following pages discuss these approaches.

6. What are tools used in process modeling?

Process modeling, sometimes called structured analysis and design, is an analysis and design technique that describes processes that transform inputs into outputs. Tools that a systems analyst uses for process modeling include entity-relationship diagrams, data flow diagrams, and the project dictionary. An entity-relationship diagram (ERD) is a tool that graphically shows the connections among entities in a system. An entity is an object in the system that has data. For example, a school might have student, grades, class, room, and instructor entities. On the ERD, entity names usually are nouns written in all capital letters. Each relationship describes a connection between two entities. In the ERD shown in Figure 12-7, a class contains one or more students, is taught by one instructor, and may or may not be held in a room. A student may or may not take classes in a given semester and, similarly, may or may not earn grades. It is important that the systems analyst has an accurate understanding of the system. The systems analyst reviews the ERD with the user. After users approve the ERD, the systems analyst identifies data items associated with an entity. For example, the STUDENT entity might have these data items: Student ID, First Name, Last Name, Address, City, State, Postal Code, E-mail Address, Date Admitted, Major, and Photo. A data flow diagram (DFD) is a tool that graphically shows the flow of data in a system. The key elements of a DFD are the data flows, the processes, the data stores, and the sources. A data flow, indicated by a line with an arrow, shows the input or output of data or information into or out from a process. A process, which is drawn as a circle, transforms an input data flow into an output data flow. A data store, shown as a rectangle with no sides, is a holding place for data and information. Examples of data stores are filing cabinets, checkbook registers, or electronic files stored on a computer. A source, drawn as a square, identifies an entity outside the scope of the system. Sources send data into the system or receive information from the system. The project dictionary, sometimes called the repository, contains all the documentation and deliverables of a project. The project dictionary helps everyone keep track of the huge amount of details in a system. The dictionary explains every item found on DFDs and ERDs. Each process, data store, data flow, and source on every DFD has an entry in the project dictionary. Every entity on the ERD has an entry in the project dictionary. The dictionary also contains an entry for each data item associated with the entities. The number of entries added to the dictionary at this point can be enormous. Thus, this activity requires a lot of time. The systems analyst uses a variety of techniques to enter these items in the project dictionary. Some of these include structured English, decision tables and decision trees, and the data dictionary.

7. What are tools used in object modeling?

Object modeling can use the same tools as those used in process modeling. Many systems analysts, however, choose to use tools defined in the UML. Although used in all types of business modeling, the UML (Unified Modeling Language) has been adopted as a standard notation for object modeling and development. The UML is a graphical tool that enables analysts to document a system. It consists of many inter related diagrams. Each diagram conveys a view of the system. The latest UML version includes 13 different diagrams to assist the analyst in modeling the system. Two of the more common tools are the use case diagram and class diagram. A use case diagram graphically shows how actors interact with the information system. An actor is a user or other entity such as a program. The function that the actor can perform is called the use case. Thus, a use case diagram shows actors and their use cases. The actor is drawn as a stick figure that connects to each use case with an arrow. Because these diagrams are easy to understand, analysts find that the use case diagram is an ideal tool for communicating system requirements with users. A class diagram graphically shows classes and subclasses in a system (Figure 12-14). On a class diagram, objects are grouped into classes. Each class can have one or more lower levels called subclasses. Each subclass inherits the methods and attributes of the objects in its higher-level class. Every object in a class shares methods and attributes that are part of its higher-level class. This concept of lower levels inheriting methods and attributes of higher levels is called inheritance.

8. What activities are performed in the design phase?

The design phase consists of two major activities: (1) if necessary, acquire hardware and software and (2) develop all of the details of the new or modified information system. The systems analyst often performs these two activities at the same time instead of sequentially. When the steering committee approves a solution, the systems analyst begins the activity of obtaining additional hardware or software or evaluating cloud storage providers that offer the hardware or software to meet the organization’s needs. The systems analyst may skip this activity if the approved solution does not require new hardware or software. If this activity is required, the selection of appropriate products or providers is crucial for the success of the information system. The activity consists of four major tasks: (1) identify technical specifications, (2) solicit vendor proposals, (3) test and evaluate vendor proposals, and (4) make a decision. After the systems analyst identifies the data and process requirements, the next step is to develop detailed design specifications for the components in the proposed solution. A detailed design sometimes is called a physical design because it specifies hardware and software — the physical components required — for automated procedures. The activities to be performed include developing designs for the databases, inputs, outputs, and programs. The length and complexity of these activities vary depending on previous decisions. For example, the systems analyst may skip many of these activities when purchasing packaged software. If an organization is developing custom software, however, these activities can be quite time-consuming.

9. Why is program development part of system development?

During the design phase, an organization can purchase packaged software, which is mass-produced, copyrighted, prewritten software. If suitable packaged software is not available, however, a company may opt for custom software, which is application software developed at the user’s request to match the user’s requirements exactly. Programmers write custom software from the program specification package created during the analysis phase, following an organized set of activities known as the program development life cycle.

10. What activities are performed in the implementation phase?

The purpose of the implementation phase is to construct, or build, the new or modified system and then deliver it to the users. Members of the system development team perform four major activities in this phase: (1) develop programs, (2) install and test the new system, (3) train users, and (4) convert to the new system. If the organization purchases packaged software and no modifications to the software are required, the development team may skip this activity. For custom software or packaged software that requires modification, however, programs are developed or modified either by an outside firm or in-house. Programmers write or modify programs from the program specification package created during the analysis phase. Just as system development follows an organized set of activities, so does program development. These program development activities are known as the program development life cycle. If the organization acquires new hardware or software, someone must install and test it. The systems analysts should test individual programs. They also should be sure that all the programs work together in the system. Systems analysts do not want errors in the system after it is delivered to the users. According to a recent study, poor user training is one of the top ten reasons why system development projects fail. Users must be trained properly on a system’s functionality. Training involves showing users exactly how they will use the new hardware and software in the system. Some training takes place as one-on-one sessions or classroom style lectures. Other organizations use Web-based training, which is a self-directed, self-paced online instruction technique. Whichever method is used, it should include hands-on sessions with realistic sample data. The final implementation activity is to change from the old system to the new system. This change can take place using one or more of the following conversion strategies: direct, parallel, phased, or pilot.

11. What activities are performed in the operations, support, and security phase?

The purpose of the operation, support, and security phase is to provide ongoing assistance for an information system and its users after the system is implemented. The operation, support, and security phase consists of three major activities: (1) perform maintenance activities, (2) monitor system performance, and (3) assess system security. Information system maintenance activities include fixing errors in, as well as improving, a system’s operations. To determine initial maintenance needs, the systems analyst should meet with users. The purpose of this meeting, called the post-implementation system review, is to discover whether the information system is performing according to the users’ expectations. Sometimes users identify errors in the system. Problems with design (logic) usually are the cause of these errors. For example, the total of a column might be incorrect. These types of errors return the analyst to the planning phase to perform corrective maintenance, which is the process of diagnosing and correcting errors in an information system. Sometimes, users have enhancements or additional requirements that involve modifying or expanding an existing information system. Adaptive maintenance is the process of including new features or capabilities in an information system. To perform adaptive maintenance, the analyst returns to the planning phase. During this phase, the systems analyst monitors performance of the new or modified information system. The purpose of performance monitoring is to determine whether the system is inefficient or unstable at any point. If it is, the systems analyst must investigate solutions to make the information system more efficient and reliable, a process called perfective maintenance — back to the planning phase. Most organizations must deal with complex computer security issues. All elements of an information system — hardware, software, data, people, and procedures — must be secure from threats both inside and outside the enterprise. For example, users should be allowed access only to the data and information for which they are authorized, which typically is limited to the amount necessary to do their job. Data should be secure so that intruders cannot alter, damage, or steal data. Networks need safeguards to prevent them from being compromised. If any vulnerabilities are detected, the analyst returns to the planning phase to investigate techniques to safeguard the information system.