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Introduction to Computing
Slides By ADEELA MUSTAFA
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Information System Development (12th –Chapter)
What Is System Development? A system is a set of components that interact to achieve a common goal. An information system (IS) is a collection of hardware, software, data, people, and procedures that work together to produce quality information. An information system supports daily, short-term, and long-range activities of users. As time passes, the type of information that users need often changes. A sales manager may want the weekly summary report grouped by district today and by product tomorrow. When information requirements change, the information system must meet the new requirements. In some cases, the members of the system development team modify the current information system. In other cases, they develop an entirely new information system.
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Information System Development
System development is a set of activities used to build an information system. System Development Phases 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
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System development often consists of five phases that form a loop. Several ongoing activities also take place throughout system development.
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Information System Development
Documentation 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.
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Information System Development
Data and Information Gathering Techniques During system development, members of the project team gather data and information. They need accurate and timely data and information for many reasons. They review documentation, 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.
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Information System Development
• 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. To learn more about how to conduct an interview. • 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
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During a JAD session, the systems analyst is the moderator, or leader, of the discussion. Another member, called the scribe, records facts and action items assigned during the session.
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Information System Development
• 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.
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Information System Development
What Initiates a System Development Project? A user may request a new or modified information system for a variety of reasons. The most obvious reason is to correct a problem such as an incorrect calculation or a security breach. Another reason is to improve the information system. For example, if a school wants student report cards to be generated automatically from instructors’ online grade books, it would have to modify the existing registration system to include this new feature. Organizations may want to improve hardware, software, or other technology to enhance an information system. A user may request a new or modified information system verbally in a telephone conversation or written as an message, In larger organizations, users write a formal request for a new or modified information system, which is called a request for system services or project request
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Sometimes users informally communicate a project request verbally or as an message. In larger organizations, requests often are documented on a form such as this Request for System Services.
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Information System Development
Planning Phase The planning phase for a project begins when the steering committee receives a project request. 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.
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Information System Development
Analysis Phase The analysis phase consists of two major activities: (1) conduct a preliminary investigation and (2) perform detailed analysis. The 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. 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.
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A feasibility report presents the results of the preliminary investigation. The report must be prepared professionally and be well organized to be effective.
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Information System Development
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.
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Information System Development
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.
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Information System Development
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. Acquiring Necessary 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 systems analyst may skip this activity if the approved solution does not require new hardware or software.
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Information System Development
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.
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Information System Development
Database Design During database design, the systems analyst builds upon the data dictionary developed during the analysis phase. The systems analyst works closely with the database analysts and database administrators to identify those data elements that currently exist within the organizations and those that are new. With relational database systems, the systems analyst defines the structure of each table in the system, as well as relationships among the tables. The systems analyst also addresses user access privileges. That is, the systems analyst defines which data elements each user can access, when they can access the data elements, what actions they can perform on the data elements, and under what circumstances they can access the elements. The result of database design is called a data model.
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Information System Development
Detailed Design 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. Program Design During program design, the systems analyst prepares the program specification package, which identifies the required programs and the relationship among each program, as well as the input, output, and database specifications.
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Users must give their approval on
all inputs and outputs. This input screen is a mockup (containing actual sample data) for users to review.
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Information System Development
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.
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Information System Development
Operation, 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.
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Information System Development
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.
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Information System Development
Developing a Computer Security Plan An important responsibility of the CSO is to develop a computer security plan. A computer security plan summarizes in writing all of the safeguards that are in place to protect an organization’s information assets. A computer security plan should do the following: 1. Identify all information assets of an organization, including hardware, software, documentation, procedures, people, data, facilities, and supplies. 2. Identify all security risks that may cause an information asset loss. Rank risks from most likely to least likely to occur. Place an estimated value on each risk, including lost business. For example, what is the estimated loss if customers cannot access computers for one hour, one day, or one week? 3. For each risk, identify the safeguards that exist to detect, prevent, and recover from a loss.
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End Thank You All (have a nice day)
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