154515System Development Life Cycle: SDLC

154515

System Development Life Cycle: SDLC

The system development cycle also known as SDLC for short, is a method that system analysts use to develop systems. in order to use the sequence of events or activities that must be done first or later In order to help develop the system easier. which system analysts must clearly understand It is correct that at each step, what must be done and how to achieve the desired results. Generally, the system development lifecycle is made up of different phases. Each step contains the details of several operations. as well as set goals for each step of the work And must show the progress of the project that has been done in each step. There must be a report to show the results of each step. to propose to the management to consider and decide will be carried out in the next stage of system development. Or change the direction of doing that project? Or if any stage of the system development process is not clear enough for the management to make a decision, the system analyst may have to go back to study the details of the work in the previous step again. until the management is able to make a decision The system development cycle is divided into 7 steps as follows:

Show system development cycle Also known as SDLC in system development. Often popularly prepared as a project called. Project Management (Project Management) is planned to work in different steps, including 7 steps, starting from the problem determination stage. project feasibility study system analysis system design Build or develop a system or develop a system

1. Problem determination
2. Feasibility study
3. System analysis
4. System design
5. System construction
6. Installing the SDLC
7. Evaluation and system maintenance

Step 1 Determining the Problem (Problem Definition)

The problem determination or understanding the problem as the initial stage of system development The system analyst must understand the problems that arise. and user needs to find a new system approach that will meet the needs of users And can solve business problems, so this step is the most important step. Because the results of the implementation in the problem determination stage are:

Goals for the entire project. This will be the direction of the project
Scope of the project. in determining the problem or understanding the problem must define activities of the work system that can be changed Determine the part of the work system that is beyond the scope of the project, including the limitations and conditions of the project
The amount of funds required for the project. including the start and end date of work at each step with a rough estimate with the expected number of personnel required for each step.

Step 2 Feasibility Study

The feasibility study is a preliminary study The aim is to find out what possible ways of doing the project. which may have several approaches that can solve system problems at the least cost and time To obtain satisfactory results, the proposed approaches must be proven to be appropriate or feasible. and must be accepted by the executives, system analysts must study to make it clear that The solution to that problem Is it possible? In general, in the feasibility study
It considers 3 factors which are

Technical Feasibility
Operational Feasibility
Economic Feasibility

Technical Feasibility Technical

Feasibility or technology will check whether The organization has computers, software, peripherals. including other related tools or how many Is it enough? If so, what level is the computer’s performance? If not, where can I buy it? Where can I buy it? In addition, the software must be developed. or have to buy a new one, etc.

Operational Feasibility

A feasibility study in practice. Systems analysts will need to consider each approach to address that problem. Must meet the needs of users of the system or not. Will it affect the way users work on the system or not, and how satisfied with the new system?
knowledge and abilities, and whether there are sufficient numbers If it’s not enough, can I find it? and whether the new system is compatible with the functioning of the existing system or not

Economic Feasibility

Investment Feasibility Study It examines the cost of the project as well as the time it takes to develop the system. Considering that the goals of the project that have been set Can it be accomplished within the specified limit? and if all the next steps of the project are completed until the end Will it be worth the investment? Will the profit or benefits from the new system be worth the investment or not? to change the system The management will decide whether to proceed further in the analysis process. or to cancel the project entirely system analyst These three possibilities must be considered in order to select the most feasible approach to system development. possible solution along with cost estimates and expected profit including other details that the new system needs to use

Step 3 System Analysis

System analysis It is the process of studying the work of the old system. (Current) to find out how it works, what it does, and what problems arise. or how users want the system to change What parts of the system have been changed? Or what do you want the new system to do? Systems analysts are required to collect various information. of the organization in order to prepare a report on the work of the system This will require data collection techniques (Fact – GatheringTechniques) by studying the documents that the system is currently using.

Examining the current working methods by observing questionnaire use Interviews with users and administrators, including those involved in the data collection system by studying various documents. at that organization Active in the current work system, including the chart of personnel management in the organization. operation manual Various reporting forms used circulating in the system. This may allow system analysts to discover errors or glitches.

This causes problems from the old system, for example, when a salesperson receives a purchase order from a customer. How will there be a workflow such as how to enter the order information, how to receive payment? The system analyst may have to observe the work in each step of the personnel involved. This will allow them to understand and see how the system actually works, which will enable them to discover what the key points of the system are.

Additionally, systems analysts may need to interview users and system administrators. to know how it works What changes do you want? what dissatisfaction Inconvenience of working flexibility because the system user and executives will be people who have expertise in their duties in practice This will be able to provide information that is relevant to the needs of systems analysts. to be used in the next system design.

Therefore, if systems analysts can define the requirements clearly and accurately, it will be easier to develop a new system in the next step. But if the requirements are not correct will make the newly developed system It can fail and damage once the system analyst has collected the system requirements information. may bring such demand information Collected, written as an “experimental” (Prototype), which may be written in various computer languages. And to help make it easier, including the 4th Generation Language (Fourth Generation Language), which can do experiments to offer users. for users to see new system to be developed how does it work What is the format? what can work Does it meet the user’s needs?

If there is still something wrong or does not meet the needs of the user It can be corrected immediately. before it is actually developed, so the trial model will help reduce potential errors. (Prototype), which may be written in various computer languages. And to help make it easier, including the 4th Generation Language (Fourth Generation Language), which can do experiments to offer users. for users to see new system to be developed how does it work What is the format? what can work Does it meet the user’s needs?

When performed in the system analysis step A summary report must be written as a specific problem (Problem Specification), which contains a diagram showing the details of the system. The diagram describes the operation of the system. system information And the direction of the transmission of information of the system, so the report at this stage will consist of

Details of the work of the original system. A schematic diagram of the system’s working process should be written with a description of the diagram
the goals of the new system By writing a diagram showing the operation of the new system with a description of the diagram
Estimated cost – profit in the implementation of the new system.
A more detailed description of how the system works and problem descriptions than those described in the problem determination process based on user and management needs will be used as a guide in determining the objectives of the system. next new and at this stage Management will consider that Is it feasible for the intended purpose? If the objectives are feasible, then proceed to the next step. is to design the system further.

Step 4 System Design

System design will propose a new system where the system designer will design a new system or change the existing program new database design or change the existing database Design details about the user’s work. and must select the equipment required to install the system To create a new system, what will be required, such as the performance and features of the computer that will be used? Systems analysts must also recommend that the computer that will be used in the new system Should buy or rent or use what you already have Software required for the operation of the new system. can specify that What software must be purchased? or developed by yourself If you have to develop yourself Will use programmers that are within the agency itself or will be hired from

Outside the agency generally in the system design. A broad design process will be initiated first by the system designer. will apply the guidelines that have been studied in the feasibility study process Let’s look at it in detail, which proposes a new system’s workflow for only the main steps or changes some of the functionality of an existing system. Determine the input and output data, which part of the work will be performed.

Must use a computer to work. And which parts can still be operated by hand? and calculating the costs that will be required in the new project. should choose the most appropriate approach and then begin to proceed with the detailed design such as the database, the form for the input (input Form) and exit information or system results, such as report design (Report Format), design of display on the screen (Screen Format), data entry (Input), calculations (Calculate), data storage (Stored), design of the use of data structures (File) Structure), storage device (Storage device), data processing (Process data), backup (Backup) and program design for security (Security) of the system.

Determining the number of personnel required to operate in the system. new addition Must provide a manual explaining the working procedures in detail for the users of the system. and the design of the interface between the user of the system and the computer.

The result of this step is to present the computer and related equipment. Features of the computer and such devices to be used with the new system database preparation tasks that system users have to do various forms Both the input and output data, including the communication between the user of the system and the computer.

Step 5 Creating a system or developing a system (System Construction)

Creating a system or developing a system It builds each component of the system by starting to write programs and test programs, developing interfaces between users and the system and from databases from various system data. Programmers write programs based on the data obtained from system analysis and design. This should be reviewed with the program’s performance with system analysts.

To find out where the error might occur. To test a program is the programmer’s job. to be tested with a selected set of data which may be selected by the user This ensures that the program is faultless. After writing and testing the program has been completed successfully. User manual must be written. Dictionary (DataDictionary) section of help (Help) on the screen, etc. After completing this step will get a program that runs the new system User Manual and documents related to the use of the new system. Completed and ready to go to the next step is to install the system.

Step 6 System Implementation

System installation will bring various components that have been created in the process of creating or developing a system to install for real work in the system installation can be done in 2 ways:
Method 1 Install and use the new system alongside the old system. This is the safest way to prevent damage from malfunctioning of the new system. But it’s a very costly way. And users do not like repetitive work at the same time.

Method 2: Convert to a new system by stopping the old system. This method has a very high risk of damage. If the new system malfunctions and that mistake It happens easily Because users are not used to working with the new system, they also need to train users to understand. It can be used and works without any errors or problems. Writing procedures Determine the installation schedule, which tasks should be performed and when. and how long does it take and the creation of a control center Determine the person or group?

The people are responsible. Determining who has authority to make changes that need to be made to the new system and writing a report notifying those affected by the change after this step is successful. If users can understand and can work with the new system skillfully, then it can be considered that this system development project. has been done successfully This will be the next step of the performance evaluation. and system maintenance.

Step 7 System Evaluation and Maintenance (Post – implementation reviews and maintenance)

Evaluation and maintenance of the system It is the last step of system development. After the process of installing the system and having used the new system for quite some time The performance of the system must be evaluated. This is to verify that the new system that is installed uses this can be used for the intended purpose meet the needs of users How satisfied and accepting are users with working with the new system or what obstacles are there? must return to study the objectives or goals of the project that have been set that this new system Can work achieve the desired or not. System performance evaluation It is often set out as a guide to decide whether the project will continue.

After evaluating the performance of the system Some system changes may be proposed for appropriateness. or in the worst case is to propose a completely new design of the system.

The maintenance of the system It is necessary to do to eliminate errors that may occur during the operation of the system. and as a guideline for improving the system to suit the new work Performing system maintenance Various information systems must be planned to match the existing funding. If there is a need to change a major part of the system, a new project must be organized. and has been carried out through the various stages of the system development cycle as mentioned above.