CONCEPT OF SYSTEM ANALYSIS DESIGN (SAD) AND THE PROCESS OF SAD
CONCEPT
System is defined as a set of elements arranged in an orderly manner to accomplish an objective. System is not a randomly arranged set. It is arranged with some logic governed by rules, regulations, principles and policies. Such an arrangement is also influenced by the objective the system desires to achieve. Systems are created to solve problems. One can think of the systems approach as an organized way of dealing with a problem. In this dynamic world, the subject system analysis and design (SAD) mainly deals with the software development activities.
For example, if a computer system is designed to perform commercial data processing, then the elements will be data entry devices, a CPU, a disk, a memory, application programs and a printer. If a computer is designed to achieve the objective of design, engineering and drawing processing, then the elements will be the graphic processor, and the languages suitable for engineering and design applications, and plotters for drawing the output.
However, a clear statement of objectives brings a precision and an order into the selection of elements and their arrangements in the system. Any disorder would create a disturbance in the system, affecting the accomplishment of the objectives.
If a system in any field is analyzed. It will be observed that it has three basic parts, which are organized in an orderly manner. These three parts can be represented in a model as shown:-
A system may have a single input and multiple outputs or may have several inputs and outputs. All the systems operate in an environment. The environment may influence the system in its design and performance. When a system is designed to achieve certain objectives, it automatically sets the boundaries for itself. The understanding of boundaries of the system is essential to bring clarity in explaining the system components and their arrangements.
A collection of component that works together to realize some objectives forms a system. In a system, the different components are connected with each other and they are interdependent. For example, the human body represents a completely natural system. We are also bound by many national systems such as political system, economic system, educational system and so forth. The objective of the system demands that some output is produced as a result of processing suitable inputs. A well-designed system also includes an additional element referred to as ‘control’ that provides feedback to achieve the desired objectives of the system.
The system can be classified in different categories based on the predictability of its output and the degree of information exchange with the environment. A system is called deterministic when the inputs, the process, and outputs are known with certainty. In a deterministic system, when the output can only be predicted in probabilistic terms. The accounting system is a probabilistic one. A deterministic system operates in a predictable manner while a probabilistic system behavior is not predictable.
If a system is functioning is separated from the environment, then the system does not have any exchange with the environment nor is it influenced by the environmental changes then it is called an open system. All kinds of accounting systems, for example, cash, stocks, attendance of employees, are closed systems. Most of the systems based on rules and principles are closed systems.
The systems which are required to respond to changes in the environment such as marketing, communication, and forecasting are open systems. All open systems must have a self-organizing ability and a sensitivity to absorb and adjust to the business organization systems of manufacturing are closed systems.
The information system is a combination of a person (the user of information), the hardware-software system is a closed deterministic system but in combination with the user, it is an open and a probabilistic system.
Generally, the deterministic systems are closed, and the probabilistic systems are open. The deterministic and the closed systems are easy to computerize as they are based on facts and their behavior can be predicted with certainty. A fixed deposit accounting system, an invoicing system, and share accounting systems are examples of a closed and deterministic system.
The probabilistic system and the open systems are complex in every aspect. Hence, they call for a considerable amount of checks and controls so that the system behavior on the performance can be controlled. All such systems must ideally have self-organizing corrective system to keep the system going its desired path.
For example, the pricing systems are probabilistic and open. They are to be so designed that the changes in the taxes and duties, the purchase price and the supply positions are taken care of, in the sales price computation. Since the pricing system operates under the influence of the environment, it has to be designed with flexible computing routines to determine the price. The building of self-organizing processing routines to respond to the environmental influences is a complex task both in terms of design and operations of the system.
System analysis
System analysis may be understood as a process of collecting and interpreting facts, identifying problems and using the information to recommend improvements in the system. In other words system analysis means identification, understanding and examine the system for achieving predetermined goals/objectives of the system. System analysis is carried out with the following two objectives:-
1. To know how a system currently operates and
2. To identify the user's requirements in the proposed system
Basically, system analysis is a detailed study of all important business aspects under consideration and the existing system, and thus, the study becomes a basis for the proposed system (maybe a modified or an altogether new system). System analysis is regarded as a logical process. The emphasis in this phase is an investigation to know how the system is currently operating and to determine what must be done to solve the problem.
The system analysis phase is very important in the total development efforts of a system. The user may be aware of the problem but may not know how to solve it. During system analysis, the developer (system designer) works with the user to develop a logical model of the system. A system analyst, because of his technical background, may move too quickly to program design to make the system prematurely physical, which is not desirable and may affect the ultimate success of the system. In order to avoid this, the system analyst must involve the user at this stage to get complex information about the system. This can be achieved if a logical model of the system is developed on the basis of detailed study. Such a study (analysis) should be done by using various modern tools and techniques, such as data flow diagrams, data dictionary, and a rough description of the relevant algorithm the final requirement of proposed information system.
System analysis is a process of collecting factual data, understanding the process involved, identifying problems and recommending a feasible suggestion for improving the system functioning. This involves studying the business processes, gathering operational data, understand the information flow, finding out bottlenecks and evolving solutions for overcoming the weakness of the system so as to achieve the organizational goals. System analysis also includes subdividing of a complex process involving the entire system, identification of data store and manual process.
The major objectives of system analysis are to find answers for each business process: what is being done how is it being done, who is doing it, when is he doing it, why is it being done and how can it be improved? It is more of a thinking process and involves the creative skills of the system analyst. It attempts to give birth to a new efficient system that satisfies the current needs of the user and has scope for future growth within the organizational constraints. The result of this process is logical system design. System analysis is an interactive process that continues until a preferred and acceptable solution emerges.
SYSTEM DESIGN
Based on the user requirements and the detailed analysis of the existing system, the new system must be designed. This is the phase of system designing. It is the most crucial phase in the development of a system. The logical system design arrived at as a result of system analysis is converted into physical system design. Normally, the design proceeds in two stages:
PRELIMINARY OR GENERAL DESIGN
In the preliminary or general design, the features of the new system are specified. The costs of implementing these features and the benefits to be derived are estimated. If the project is still considered to be feasible (possible), we move to the detailed design stage.
STRUCTURED OR DETAILED DESIGN
In the detailed design stage, computer-oriented work begins in earnest. At this stage, the design of the system becomes more structured. The structure design is a blueprint of a computer system solution to a given problem having the same components and inter-relationships among the same components as the original problem. Input, output, databases, forms, codifications schemes and processing specifications are drawn up in detail. In the design stage, the programming language and the hardware and software platform in which the new system will run are also decided.
The system design involves:-
I. Defining precisely the required system output
II. Determining the data required for producing the output
III. Determining the medium and format of files and databases
IV. Devising processing methods and use of software to produce output
V. Determine the methods of data capture data input
VI. Designing input forms
VII. Designing codification schemed
VIII. Detailed manual procedures
IX. Documenting the design
SYSTEM ANALYSIS AND DESIGN
SAD, as performed by the system analysts, seeks to understand what human need to analyze data input or data flow systematically, process information in the context of a particular business. Furthermore, system analysis and design are used to analyze, design and implements in the support of users and the functioning of business that can be accomplished through the use of a computerized information system.
Installing a system without proper planning leads to great user dissatisfaction and frequently causes the system to fall into disuse. System analysis and design lend structure to the analysis and design of information systems, a costly endeavor that might otherwise have been done in a haphazard way. It can be thought of as a series of processes systematically undertaken to improve a business through the use of a computerized information system. SAD involves working with current and eventual users of an information system to support them in working with technologies in an organizational setting.
REQUIREMENT DETERMINATION
It is also termed as a part of software requirement specification (SRS); it is the starting point of the system development activity. This activity is considered as the most difficult and also the most error-prone activity because of the communication gap between the user and the developer. This may be because the user usually does not understand the user's problem and application area. The requirement determination is a means of translating the ideas given by the user, into a formal document, and thus to bridge the communication gap. A good SRS provides the following benefits:-
· It bridges the communication gap between the user and the developer by acting as a basis of the agreement between the two parties.
· It reduces the development cost by overcoming errors and misunderstandings early in the development.
· It becomes a basis of reference for validation of the final product and thus acts as a benchmark.
Requirement determination consists of three activities namely requirement anticipation, requirement investigation, and requirement specification. A requirement anticipation activity includes the past experience of the analysis when influencing the study. They may force the likelihood of certain problems or features and requirements for a new system. Thus, the background of the analysts to know what to ask or which aspects to investigate can be useful in at the system investigation. Requirement investigation is at the center of system analysis. In this, the existing system is studied and documented for further analysis. Various methods like fact-finding techniques are used for the investigation are analyzed to determine requirement specification, which is the description of the features for a proposed system.
Requirement determination, in fact, is to learn and collect the information about:-
ü The basic process
ü The data which is used or produced during the process
ü The various constraints in terms of time and volume of work and
ü The performance controls used in the system.
UNDERSTAND THE PROCESS
Process understanding can be acquired, if the information is collected regarding:-
ü The purpose of the business activity
ü The steps which and where they are performed
ü The persons performing them, and
ü The frequency, time and user of the resulting information
Identify data used and information generated
Next to process understanding, an information analyst should find out what data is used to perform each activity.
Determine the frequency, timing, and volume.
Information should also be collected to know how often the activity is repeated and the volume of items to be handled. Similarly, timing does affect the way analysts evaluate certain steps in carrying out an activity, in other words, timing, frequency and volume of activities are important facts to collect.
Know the performance controls
System controls enable analysts to understand how business functions can be maintained in an acceptable manner.
In order to understand the business operations of the organizations and thus to know the existing system and information requirement for the new system and information analyst collects the information and then makes an analysis of the collected information by using certain analytics tools.
Strategies for requirement determination
In order to collect information so as to study the existing system and to determine information requirement, there are different strategies, which could be used for the purpose. These strategies are discussed below:-
Interview: the interview is a face-to-face method used for collecting the required data. In this method, a person (the interviewer) asks a question from the other person being interviewed. The interview may be formal or informal and the question asked may be structured or unstructured. The interview is the oldest and the most often used device for gathering information about an existing system.
Because of the time required for interviewing and the inability of the users to explain the system in detail, other methods are also used to gather information. Interviewing is regarded as an art and it is important that analysts must be trained in the art of successful interviewing. This is also important because of the fact that the success of an interviewer and on his or her preparation for the interview.
Questionnaire: a questionnaire is a term used for almost any tool that has questions to which individual respond. The use of questionnaires allows analysts to collect information about various aspects of a system from a large number of persons. The questionnaire may give more reliable data than other fact-finding techniques. Also, the wide distribution ensures greater uncertainty for responses. The questionnaire survey also helps in saving time as compared to interviews. The analysts should know the advantages and disadvantages of structured as well as unstructured questionnaires must be tested and modified as per the background and experience of the respondents.
Record review: record review is also known as a review of documentation. Its main purpose is to establish quantitative information regarding volumes, frequencies, trends, ratios, etc. in record review; analysts examine information that has been recorded about the system and its users. Records/documents may include written policy manuals, regulations and standard operating procedures used by the organization as a guide for managers and other employees. Procedures, manuals, and forms are useful sources for the analysts to study the existing system.
Observation: another information gathering tool used in system studies is observation. It is the process of recognizing and noticing people, objects, and occurrences to obtain information. Observation allows analysis to get information. This is difficult to obtain by any other fact-finding method. This approach is most useful when analysts need to actually observe the way documents are handled, Processes are carried out and whether specific steps are actually followed. As an observer, the analyst follows a set of rules. While making observations, he/she is more likely to listen than talk.
The analysis usually uses a combination of all these approached to study an existing system as anyone approach may not be sufficient for electing information requirement of the system.
SUMMARY
System analysis is a detailed study of all important business aspects of a future system, as well as the existing system. Thus, the study becomes a basis for a proposed system. In this process of system analysis, the emphasis is placed on ‘what must be done to solve the problem’. The final product of system analysis is a set of system requirement of a proposed information system. Requirement determination, which is an important activity of system analysis, is a means of translating the ideas given by the users into a formal document. System analysis ensures that the system analyst understands the user’s requirements in a clear way and thus reduces the communication gap between the user and the developer. It reduces the development cost by overcoming errors and misunderstandings early in the development and becomes a basis for reference for validation of the final product.
In order to study the existing system and to determine information requirements, there are several strategies which could be used for the purpose. These strategies may include interviews, questionnaires, record reviews, and observation. As anyone may not be sufficient for electing information requirements of the system, the analysis usually uses a combination of all these strategies.
System analysis is carried out with the help of certain tools. The main tools, which are used for analyzing and documenting the system specification, are data flow diagram, data dictionary, structured English, decision trees and decisions tables.
The main objectives of the system design are to produce system specifications which can then be converted into an information system for use in the organization. However, the system design is a creative activity and is considered to evolve through two different levels of design, i.e. conceptual and detailed design. The conceptual design which is also called feasibility design sets the direction for the MIS project and provides performance requirements. The output of the conceptual design i.e. performance specifications is taken as an input to the detailed design to produce system specifications. The system specifications thus generated are handed over to the computer programmer for translating into a physical information system.
The system specifications, called detailed system design or logical system design provide all details of inputs, outputs, file, database controls, and procedures. For ensuring an effective, efficient and successful MIS, the system analysts must not rush through this phase, rather each and every step must be undertaken very carefully to prepare a detailed system design.