Chapter 12 Review Discovering Computers - Student Assignment (Mr. Tri Djoko Wahjono, Ir.,M.Sc)

Discovering Computers

Student Assignment - Chapter 12 Review

Name         : Anneke Dwi Sesarika Rahmanto

Class          : 01PCT

Student ID : 1701316166

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

1.     What Is System Development, and What Are the System Development Phases?

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:

1. Planning

2. Analysis

3. Design

4. Implementation

5. 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.

2. What Are Guidelines for System Development?

1. Group activities or tasks into phases: Many SDLCs contain the same phases. Others have more or fewer phases. Regardless, all SDLCs have similar activities. 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.     Why 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. For larger projects, project management activities often are separated between a project manager and a project leader. Some organizations use extreme project management. The project leader identifies the scope of the project, required activities, time estimates, cost estimates, the order of activities, and activities that can take place simultaneously. The project leader records this information in a project plan.

Feasibility is a measure of how suitable the development of a system will be to the organization. A systems analyst typically uses four tests to evaluate feasibility of a project: operational feasibility, which measures how well the proposed system will work; schedule feasibility, which measures whether established project deadlines are reasonable; technical feasibility, which measures whether the organization has or can obtain the hardware, software, and people to deliver and then support the system; and economic feasibility, also called cost/benefit feasibility, which measures whether the lifetime benefits of the proposed system will be greater than its lifetime costs.

Documentation is the collection and summarization of data and information and includes reports, diagrams, programs, or other deliverables. A project notebook contains all documentation for a single project.

 To gather data and information, systems analysts and other IT professionals review documentation, observe, survey, interview, participate in joint-application design ( JAD) sessions, and research.

4.     What Activities Are Performed in the Planning Phase?

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?

(1)   conduct a preliminary investigation

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. 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.

(2)   perform detailed analysis.

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. 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.

6.     What Are Tools Used in Process Modeling?

Tools that a systems analyst uses for process modeling include entity-relationship diagrams, data flow diagrams, and the project dictionary.

Entity-Relationship Diagrams

 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. 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.

Data Flow Diagrams

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.

Project Dictionary

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.

7.     What Are Tools Used in Object Modeling?

Object modeling, sometimes called object-oriented (OO) analysis and design, combines the data with processes that act on the data into a single unit, called an object. Object modeling can use the same tools as those used in process modeling, but the UML (Unified Modeling Language) has been adopted as a standard notation for object modeling and development. Two common tools in the UML are the use case diagram and the class diagram. A use case diagram graphically shows how actors interact with the information system. An actor is a user or other entity, and the use case is the function that the actor can perform. A class diagram graphically shows classes and one or more lower levels, called subclasses, in a system. Lower levels (subclasses) contain attributes of higher levels (classes) in a concept 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

Acquire hardware and software ;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 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. Detailed design includes developing designs for the databases, inputs, outputs, and programs. During detailed design, many systems analysts use a prototype, which is a working model of the proposed system. Computer-aided software engineering (CASE) products are tools designed to support one or more activities of system development.

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. System developers 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.

The program development life cycle follows these six steps: (1) analyze the requirements, (2) design the solution, (3) validate the design, (4) implement the design, (5) test the solution, and (6) document the solution.

Systems analysts and users develop test data so that they can perform various tests. The test data should include both valid (correct) and invalid (incorrect) data. When valid test data is entered, the program should produce the correct results. Invalid test data should generate an error. Tests performed during this step include unit tests, systems tests, integration tests, and acceptance tests.

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.

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 operations, support, and security phase consists of three major activities: (1) perform maintenance activities, (2) monitor system performance, and (3) assess system security. Organizations today often have a chief security officer (CSO) who is responsible for physical security of an organization’s property and people and also is in charge of securing computing resources. The CSO develops a computer security plan, which summarizes in writing all safeguards that protect the organization’s information assets.