The System Development Models

                The success of making the system is depending on the development models that the system analyst used. The system development models are used as a basis in developing an information system. The system development is somehow like a plan or structure in making system that system analyst plan. The following system development models are the models, or method, or plan that the system analyst follows in their process in developing their information system.

                The structure of the system development process is always based on the phases that everybody followed in making information system that a system analyst handles a project. Even if they do something else or added phases from it, the common thing among the system development models circles around the system development life cycle which follows this phases or guidelines.

Planning

                The first thing that the system analyst does is to start the project in doing what are the needs of the information system that the client needs. The system analysts do also in planning phase is to define the problem that the client wants to be solved in order to improve the system that the client wants to improve. In defining the problem, the system analyst will identify the problem by interviewing the key users of the system. The system analyst also will make and develop the list of the expectation on business benefits or business advantage, is define in terms of its effect or influence that can cause financial benefit to the client or the sponsor of the system development. Other than making or develop the expectation on business advantage, the system analysts also identify and define the expected system capabilities. It is part of the job in the planning phase to define the scope and the limits in terms of requirement including the making a series of documents that contains problem description, business benefits, and system capabilities. The system analyst will also do the planning of what to do and what to accomplish in a specific set of days and weeks. The system analyst will plan and make a schedule for what would be the target of the specific date. The system analyst is the one that make what would be the schedule out of the limited resources that will be given to the system analyst from the client or the sponsor of the system development. Also the system analyst will plan how to make the operation of the system development process to be faster out of the schedule that the system analyst made which will be based on the resources that will be given to the system analyst. The resources of the system development can be the members of the team that the system analyst manages, the software tools that will be used in developing the system that the system analyst develops, and can also be the hardware tools and paraphernalia that the staff of the system analyst use in developing information system that the system analyst develop. In making the schedule, it is part of the job of the system analyst to develop the work breakdown structure of the project of the project that the system analyst handles. The system analyst will identify the task and activities that the team system analyst, the project manager of the system, will do or execute along the development of the information system. In making the schedule, it is part of the job in the planning phase to make a schedule using a Gant chart.  The basis of the Gant chart would be the activities and task that the team would execute along in developing the project. The system analyst, as the project manager, will also formulate the Pert Chart which will be based on the work breakdown structure which would be the individual or the subgroups’ task and activities. And as I said before, the system analyst will make schedule out of the resources available, of course, the system analyst must develop first the required resources needed in the project in making the information system which the system analyst handle. The other job in the planning phase is confirming the project feasibility. In the planning phase, it is important to determine the feasibility of the project that the system analyst handles, since it is important how feasible the project would be. The system analyst, as the project manager, will analyze what would be the feasibility of the project in terms of economic feasibility, defining if the project would cause a benefit or cost to the client or the sponsor of the project and as part of the economic feasibility analysis, the project manager will define and analyze the source of funds of the project. The system analyst also the do the organizational and cultural feasibility, technological feasibility, schedule feasibility and resource feasibility. In analyzing the organizational and cultural feasibility, the project manager must identify if the system that his team develop is fit into the culture of the company and project manager will do identifying potential risk in evaluating issues related to the system and the culture of the company. The cultural and organizational issues include low level of computer competency, computer phobia, fear employment loss which will causes usually by the automation of the system. In analyzing the technological feasibility, the project manager consider if the system is a state of the art technology, there is more consideration if the expertise needed in development the system exist in the people in the team and analyzing if there would an outside vendor to be involve in the project. In the analysis of the schedule feasibility, the system analyst as the project manager estimates what would be the need of the system even with or without complete information exist which would draw to drive realistic assumptions and estimates, recommend what time would be the range of time for the completion in order to build a completion date flexibility, assign temporary date marks to periodically reassess completion dates, the decision to involve experienced personnel, formulate the management in proper allocation of the resources. The project manager also analyze what resources are available and resources that can be acquired for the project. the project manager will analyze and define the availability of the team members that exist to work with the project, the project manager consider also the team skills and experiences of the people work for the project. the project manager will also consider the availability of the hardware and paraphernalia needed in developing the system which include the computer, equipment and supplies, and the project manager also consider the availability and time of the staff that are present to work for the system. The project manager also plan the salaries and the wages of the staff, the preparation of the equipment, training and the other things that may cause cost to the client or the sponsor of the project. Also in the planning phase and the project manager will define and analyze risk, if there exist while analyzing project feasibility, and do the risk management of the risk in doing the project in doing the information system. It is also in the planning phase that the project manager must have to know the skills and experience of the people working in the development of the system which can be done in activities such as team building but it would cost the sponsor or the client. From that planning, it would be up to the client or the sponsor of the development of the system to approve the proposal in order to let project team to start their work.

Analysis              

                The Analysis phase includes the job of defining and understanding what would be the business needs and what would be the needs in the processing of the system. The system analyst as the project manager will be defining what would be the system capabilities and constraints. System analyst will define what would be the functional needs of the system which would include the activities system must perform which will be based on procedures and business functions. The system analyst as the project manager will document the analysis models. The system analyst will define also the nonfunctional requirements of the system which would be the operating environment, the usability, the reliability, the security requirements, and the performance objectives of the system that the system analyst develops. The requirements of course would depend on the people with interest in successful system implementation, the one who will benefit the success of the system or the stakeholders of the system, and they would be the direct user of the system, the clients or the sponsor of the project of the system development, and the technical staff or the one that maintain the system operation. The analyst would be the one who will analyze who would be the people that corresponds to the three types of stakeholders. The first thing to do by the system analyst is to find or gather information that will be needed in the development of the project or the system that the system analyst develops. The information will be needed by the system analyst of the project in order to understand what the business-functions that are exist, and also from what the system analyst understand on the business functions. To understand more the business functions, it is practical to make or create a model of existing system, and from the model of the existing system, it would be possible to derive the information system requirements from the existing model. The other approach in the information gathering is to identify the logical requirements of the new system then the system analyst would balance the review of existing or current business functions with the new information system or system requirements. To make the results of the analysis more reliable, the system analyst does some fact finding investigation about the existing system.

                The fact finding jobs can be done in the investigation about the business by doing some readings in the review of existing report or procedure reports and descriptions about the system if there’s any. With that, it is part of the job to know identify business rules, discrepancies, and redundancies, and the need of understanding of the processes that are in the business. The other way of doing fact finding would be to do some interview and discussion about the business processes with the user of the system. Doing this would cost time because it is time consuming and money because it would be required to do many sessions in order to meet all the users and in order to understand more about the business processing requirements. The other way is to do more observations and documentation of business process in order to have a documentation of the existing system for future references which can be documented with workflow diagrams. It would be possible that there will be variation from the office walkthrough to performing actual task. The other way of making fact finding about the business process is to build and create system prototype. Making a preliminary design of the information system that will develop. It is focused in making the business process prototype to accomplish single objective which means that the prototype is changeable. The other way would be to distribute and collect questionnaires about the system that will be given to the stakeholders of the system. This technique of gathering information would be limited and specific information can be taken from a large number of stakeholders which would be the same. In short, small information can be taken a large number of people and is not well suited for gathering detailed information. Conduct application design sessions with members of the team that are in the group. It is an expedite investigation of system requirements seeking to compress fact-finding, modeling, policy formation, and verification activities into shorter time frame. With this method, it is important to have all the stakeholders in the session. Research more about vendor solutions. It is to conduct research if the other company solved the problem but it may cause a purchase solution before understanding problem which would result for the analyst who would conduct the method to not know the detail about the problem. A system analyst can pick from those method in gathering information.

                The system analyst will develop the system requirements of the system that the system analyst develops. It is also included in the analysis phase to define the priority of the information system requirements with that the team can identify which of the requirements would need to be handled first. In analysis phase, the system analyst as the project manager, will define the prototype for feasibility and also finding and evaluating what are the alternatives in handling the problem of the system. from that the system analyst can review recommendations in the system with the management or the client.

Design

                The job here is to design what would be the functions and the operations that the system analyst wants in the information system. It would be the detail of what would be the layouts of the graphical user interface and the process of the information system that the system analyst design which would be based on the result of the analysis in the analysis phase of developing the information system along the project. At this phase there would be a design of the different screen layout. It would be here in this phase that the design of the entity-relationship diagram would be made. It would be here in this phase that the design of the data flow diagram. Data flow diagram shows how data moves through an information system and it will now show the processing steps and the program logic, it will just show what the information system does. With the collection of the dataflow diagram, a context diagram can be made out of the data flow diagram that was made. It is somewhat like a summary of all the dataflow diagram of the system. the system analyst also design a use case diagram to help them in the implementation of the information system and along the project development.

Implementation

                Here all the design will be implemented in the machine. There will be implementations of the screen layout or the layout of the graphical user interface, the implementation of the business process that will be used in the business processing, and the implementation of the data flow diagrams for the what the system will do and entity relationship diagrams for how the machine manage the database of the information system. With the help of a number of programmers, the system analyst as the project manager will guide what would be specifics of the system that should be coded. Testing the codes the information technology personnel or the programmers is part of the job in the implementation in order to have a check if there are defects in the system that may cause from the bugs of the codes or some typographic error from the programmers or from the information technology personnel.

Support or Maintenance

                There should be some technical team who will ensure the operation and the functionalities of the system in order of the system to deliver well to the user and to the businesses. After the deployment of the information system that the system analyst and the members of the team in the project works, the system analyst as the project manager will have some people that will monitor the information system and monitor. Monitoring the system may result to the new problem that the system analyst observe and may result to the initiation of a new project.

System Development Models

                When using system development lifecycle as a structure or plan of the process in making the system, the system analyst can do the system development lifecycle in two approaches. The system development lifecycle can be in one way process approach or traditional approach which can be based on the waterfall model, or the adaptive approach which can be iterative approach and can be based on the spiral model.

Waterfall model

                Also known as the waterfall model, it is the one of the most widely used model that is usually used as a structure of developing system by the system analyst. Waterfall model follows the process of the system development lifecycle it is such that the process of the waterfall model is in one direction or the structure of the plan is in linear process. The waterfall name of the model is based from the sequences of the phases of the system development lifecycle, it is like waterfall. The concept is, if the team is done in one phase, they can proceed to the next phase in the sequence of the system development lifecycle. The structure of the process of making the system of the team including the system analyst is in one direction. Meaning, the direction of the phases that the team must undergo is one direction, no turning back to the opposite direction. The phases of the system development lifecycle are planning, analysis phase, design, implementation and support or maintenance and the waterfall model can be called a traditional approach of system development lifecycle because the structure or framework of the waterfall model is done in one way approach. The waterfall model is a linear approach to the system development process and when the project ends, the system is will not be touched anymore for improvement.  

Spiral model

                The spiral model approach in making or developing a system is an iterative repetition way of doing system development lifecycle. The phases that will be based is like the waterfall model but the process of doing the project of making the information system can be done iteratively, it is just like doing the waterfall model repeatedly until the project of making the system more stable will be done. The output of each cycle will be the prototype of the project of the system that the system analyst works. The iteration is done because there is an assumption that the first cycle of the process would not be perfect and in every iteration or repetition, the aim is to refine and polish the previous result or prototype.  There would be a mini project for each of the iterations or repetitions, and the job would be getting smaller for each of the iterations or repetitions of the project of making the information undergone.

Scrum

                Scrum is the term used in rugby which means to restart the game after accidental breach or when the ball has gone out of play. In the system development, the term scrum means a method of system development that would require a fast respond to situation as rapidly as possible and fast respond to the project needs. The approach to the system development is to break the system into its subsystem or work or task that will be done and apply the waterfall model in every subsystem or task or work of a system one at a time within a certain time or in the scrum terminology, a sprint. The sprint is a basic unit of target time of work which would tend to last between a week and a month and has a deadline or having a given or allotted time to do the work. After the developing subsystems, it is possible to undergone iteration to the process in order to refine the functionality of the system. a scrum is a kind of agile system development that promotes adaptive planning, immediate and flexible response to changes and development, and having allotted or target time to do the work.