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 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 work 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, human body represents a complete 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 the suitable inputs. A well designed system also includes an additional element referred to as ‘control’ that provides a feedback to achieve 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 closed and deterministic system.
The probabilistic system and the open systems are complex in every aspect. Hence, they call for 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 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 users 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 (may be 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 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 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 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 a logical system design. System analysis is an interactive process that continues until a preferred and acceptable solution emerges.
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. Structure design is a blue print 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 decide.
The system design involves:-
I. Defining precisely the required system output
II. Determining the data requirement 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 is used to analyze, design and implements in the support of users and the functioning of business that can be accomplished through the use of 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 lends 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 computerized information system. SAD involves working with current and eventual users of information system to support them in working with technologies in an organizational setting.
THE NEED FOR SYSTEM ANALYSIS
When you are asked to computerized a system, it is necessary to analyze the system from different angles. The analysis of the system is the basic necessity for an efficient system design. The need for analysis stems from the following point of view:-
System objective: it is necessary to define the system objectives. Many a times, it is observed that the systems are historically in operation and have lost their main purpose of achievement of the objectives. The users of the system and the personnel involved are not in a position to define the objectives. Since you are going to develop a computer based system, it is necessary to redefine or reset the objectives as a reference point in context of current business requirement.
System boundaries: it is necessary to establish the system boundaries which would define the scope and the coverage of the system. This helps to short out and understand the functional boundaries in the system, and the people involved in the system. It also helps to identify the inputs and the outputs of the various subsystems, covering the entire system.
System importance: it is necessary to understand the importance of the system in the organization. This would help the designer to decide the design feature of the system. It would be possible then to position the system in relation to the other systems for deciding the design, strategy and development.
Nature of the system: the analysis of the system will help the system designer to conclude whether the system is closed type or an open, and a deterministic or a probabilistic. Such an understanding of the system is necessary prior to design the process to ensure the necessary design architecture.
Role of the system as an interface: the system, many a times, acts as an interface to the other systems. It is necessary to understand the existing role of the system, as an interface, to safeguard the interests of the other systems. Any modification or changes made should not affect the functioning or the objectives of the other system.
Participation of the user: the strategic purpose of the analysis of the people to a new development. System analysis process provides a sense of participation to the people. This helps in breaking the resistance to the new development and it also then ensures the commitment to the new development and it also then ensures the commitment to the new system.
Understanding of resource needs: the analysis of the system helps in defining the resource requirement in terms of hardware and software. Hence, if any additional resources are required, this would mean an investment from the point of view of return on such investment. If the return on such investment from the point of view of return on such an investment. If the return on the investment is not attractive, the management may drop the project.
Assessment of feasibility (practicability): the analysis of the system helps to establish the feasibility from different angles. The system should satisfy the technical economic and operational feasibility. Many a time, the systems are feasible from the technical and economic point of view, but they may be infeasible from the operational point of view. The assessment of feasibility will have the investment and the system designer’s time. It would also save the embracement to the system designer as he is viewed as the key figure in such project.
MIS AND SYSTEM ANALYSIS
System analysis plays central role in the development of the MIS. Since the MIS is a corporation of the various systems, a systematic approach in its development helps in achieving the objective of the MIS. Each system within the MIS plays a role which contributes to the accomplishment of the MIS objective.
The tools of the system analysis and the method of development enforce a discipline on the designer to follow the steps strictly as stipulated. The possibility of a mistake or an inadvertence is almost ruled out. The system analysis with its structural analysis and design approach ensures an appropriate coverage of the subsystems. The data entities and attributes are considered completely keeping in view the needs of the systems in question and their interface with other systems.
The systems analysis begins with the output design which itself ensures that the information needs are considered and displayed in the appropriate report or screen format; the subsequent design steps are taken to fulfill these needs.
The MIS may call for an open system design. In such a case while making the systems analysis and design, the aspect of open system design is considered and necessary modification are introduced in the designed the information system.
The user’s application in the system development ensures the attention to the smaller details in the design. The users actively come out with their requirements automatically ensuring that the users are met more precisely.
The systems analysis and designs, as a tool of the MIS development, helps in streamlining the procedures of the company to the current needs of the business and information objectives. New transactio0ns, new documents, new procedures are brought in to make the system more efficient before it is designed.
The SAD exercise considers testing the feasibility of the system as an important step. This step, many a times, saves the implementation of inefficient systems. Sometimes it forces the management and analysts to look into the requirement and its genuineness. The MIS development process largely relies on the systems analysis and design as a source of the scientific development of the MIS.
The development of the MIS in today advance information technology and internet, web environment is a challenge. The nature of the system analysis has undergone a change, while the core process of the analysis and development has remained the same.
The system analysis is not restricted to the data-process-output. It also covers the technologies which enables the process feasible. The subject now covers the analysis of interfacing and supports the technologies and it’s fitting into a chosen hardware-software platforms for a core system development. The MIS largely depends on how these technologies are bladed with the main system. The system architecture of the MIS is now different due to the high tech involvement of the data capture, communication, and processing technologies. The trend is towards more swift data capture and making it available in the fastest possible time leaving its usage to the user.
The development methodology may be the predictable design of data, databases and file approach or object oriented analysis and design approach. The MIS design is same, the difference is in the development cycle time, quality of information efficiency of design and the case of maintenance of the system.
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 users 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 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 influence 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 centre 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 frequency, timing and volume.
Information should also be collected to know how often the activity is repeated and 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 analysis 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 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 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 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 collects 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 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 weather 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 use a combination of all these approached to study an existing system as any one approach may not be sufficient for electing information requirement of the system.
System analysis is a detailed study of all important business aspects of a future system, as well as existing system. Thus, the study becomes a basis for a proposed system. In this process of system analysis, 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 any one may not be sufficient for electing information requirements of the system, the analysis usually use 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 are taken as an input to the detailed design to produce system specifications. The system specifications thus generated are handled 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.
SYSTEM LIFE CYCLE
System life cycle is an organizational process of developing and maintaining systems. It helps in establishing a system project plan, because it gives overall list of processes and sub-processes required for developing a system. System development life cycle means combination of various activities. In other words we can say that various activities put together are referred as system development life cycle. In the System Analysis and Design terminology, the system development life cycle also means software development life cycle. Following are the different phases of system development life cycle:
1. Feasibility study
2. Detailed system study
3. System analysis
4. System design
PHASES OF SYSTEM DEVELOPMENT LIFE CYCLE
Let us now describe the different phases and related activities of system development life cycle.
(a) Preliminary System Study
Preliminary system study is the first stage of system development life cycle. This is a brief investigation of the system under consideration and gives a clear picture of what actually the physical system is? In practice, the initial system study involves the preparation of a ‘System Proposal’ which lists the Problem Definition, Objectives of the Study, Terms of reference for Study, Constraints, and Expected benefits of the new system, etc. in the light of the user requirements. The system proposal is prepared by the System Analyst (who studies the system) and places it before the user management. The management may accept the proposal and the cycle proceeds to the next stage. The management may also reject the proposal or request some modifications in the proposal. In summary, we would say that system study phase passes through the following steps:
· l problem identification and project initiation
· l background analysis
· l inference or findings (system proposal)
(b) Feasibility Study
In case the system proposal is acceptable to the management, the next phase is to examine the feasibility of the system. The feasibility study is basically the test of the proposed system in the light of its workability, meeting user’s requirements, effective use of resources and of course, the cost effectiveness. These are categorized as technical, operational, economic and schedule feasibility. The main goal of feasibility study is not to solve the problem but to achieve the scope. In the process of feasibility study, the cost and benefits are estimated with greater accuracy to find the Return on Investment (ROI). This also defines the resources needed to complete the detailed investigation. The result is a feasibility report submitted to the management. This may be accepted or accepted with modifications or rejected. The system cycle proceeds only if the management accepts it.
(c) Detailed System Study
The detailed investigation of the system is carried out in accordance with the objectives of the proposed system. This involves detailed study of various operations performed by a system and their relationships within and outside the system. During this process, data are collected on the available files, decision points and transactions handled by the present system. Interviews, on-site observation and questionnaire are the tools used for detailed system study. Using the following steps it becomes easy to draw the exact boundary of the new system under consideration:
· Keeping in view the problems and new requirements
· Workout the pros and cons including new areas of the system
All the data and the findings must be documented in the form of detailed data flow diagrams (DFDs), data dictionary, logical data structures and miniature specification. The main points to be discussed in this stage are:
· Specification of what the new system is to accomplish based on the user requirements.
· Functional hierarchy showing the functions to be performed by the new system and their relationship with each other
· Functional network, which are similar to function hierarchy but they highlight the functions which are common to more than one procedure.
· List of attributes of the entities – these are the data items which need to be held about each entity (record)
(d) System Analysis
Systems analysis is a process of collecting factual data, understand the processes involved, identifying problems and recommending feasible suggestions 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 weaknesses of the system so as to achieve the organizational goals. System Analysis also includes subdividing of complex process involving the entire system, identification of data store and manual processes. The major objectives of systems 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 a logical system design. Systems analysis is an iterative process that continues until a preferred and acceptable solution emerges.
(e) 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 developments of a system. The logical system design arrived at as a result of systems analysis is converted into physical system design. Normally, the design proceeds in two stages:
· Preliminary or General Design
· Structured or Detailed Design
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, 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. Structure design is a blue print 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, codification 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. There are several tools and techniques used for describing the system design of the system. These tools and techniques are:
· Data flow diagram (DFD)
· Data dictionary
· Structured English
· Decision table
· Decision tree
The system design involves:
1. Defining precisely the required system output
2. Determining the data requirement for producing the output
3. Determining the medium and format of files and databases
4. Devising processing methods and use of software to produce output
5. . Determine the methods of data capture and data input
6. Designing Input forms
7. Designing Codification Schemes
8. Detailed manual procedures
9. Documenting the Design
The system design needs to be implemented to make it a workable system. This demands the coding of design into computer understandable language, i.e., programming language. This is also called the programming phase in which the programmer converts the program specifications into computer instructions, which we refer to as programs. It is an important stage where the defined procedures are transformed into control specifications by the help of a computer language. The programs coordinate the data movements and control the entire process in a system. It is generally felt that the programs must be modular in nature. This helps in fast development, maintenance and future changes, if required.
Before actually implementing the new system into operation, a test run of the system is done for removing the bugs, if any. It is an important phase of a successful system. After codifying the whole programs of the system, a test plan should be developed and run on a given set of test data. The output of the test run should match the expected results. Sometimes, system testing is considered a part of implementation process. Using the test data following test run are carried out:
· Program test
· System test
Program test: When the programs have been coded, compiled and brought to working conditions, they must be individually tested with the prepared test data. Any undesirable happening must be noted and debugged (error corrections)
System Test: After carrying out the program test for each of the programs of the system and errors removed, then system test is done. At this stage the test is done on actual data. The complete system is executed on the actual data. At each stage of the execution, the results or output of the system is analyzed. During the result analysis, it may be found that the outputs are not matching the expected output of the system. In such case, the errors in the particular programs are identified and are fixed and further tested for the expected output.
When it is ensured that the system is running error-free, the users are called with their own actual data so that the system could be shown running as per their requirements.
After having the user acceptance of the new system developed, the implementation phase begins. Implementation is the stage of a project during which theory is turned into practice. The major steps involved in this phase are:
· Acquisition and Installation of Hardware and Software
· User Training
The hardware and the relevant software required for running the system must be made fully operational before implementation. The conversion is also one of the most critical and expensive activities in the system development life cycle. The data from the old system needs to be converted to operate in the new format of the new system. The database needs to be setup with security and recovery procedures fully defined.
During this phase, all the programs of the system are loaded onto the user’s computer. After loading the system, training of the user starts. Main topics of such type of training are:
· How to execute the package
· How to enter the data
· How to process the data (processing details)
· How to take out the reports
After the users are trained about the computerized system, working has to shift from manual to computerized working. The process is called ‘Changeover’. The following strategies are followed for changeover of the system.
(I) Direct Changeover: This is the complete replacement of the old system by the new system. It is a risky approach and requires comprehensive system testing and training.
(ii) Parallel run: In parallel run both the systems, i.e., computerized and manual, are executed simultaneously for certain defined period. The same data is processed by both the systems. This strategy is less risky but more expensive because of the following:
ü Manual results can be compared with the results of the computerized system. The operational work is doubled.
ü Failure of the computerized system at the early stage does not affect the working of the organization, because the manual system continues to work, as it used to do.
(iii) Pilot run: In this type of run, the new system is run with the data from one or more of the previous periods for the whole or part of the system. The results are compared with the old system results. It is less expensive and risky than parallel run approach. This strategy builds the confidence and the errors are traced easily without affecting the operations. The documentation of the system is also one of the most important activities in the system development life cycle. This ensures the continuity of the system. There are generally two types of documentation prepared for any system. These are:
ü User or Operator Documentation
ü System Documentation
The user documentation is a complete description of the system from the user’s point of view detailing how to use or operate the system. It also includes the major error messages likely to be encountered by the users. The system documentation contains the details of system design, programs, their coding, system flow, data dictionary, process description, etc. This helps to understand the system and permit changes to be made in the existing system to satisfy new user needs.
Maintenance is necessary to eliminate errors in the system during its working life and to tune the system to any variations in its working environments. It has been seen that there are always some errors found in the systems that must be noted and corrected. It also means the review of the system from time to time. The review of the system is done for:
o knowing the full capabilities of the system
o knowing the required changes or the additional requirements
o Studying the performance.
If a major change to a system is needed, a new project may have to be set up to carry out the change. The new project will then proceed through all the above life cycle phases.