The System Development Life Cycle involves mainly the three steps or the stages and these can be summarized as the follows

1. The Definition Stage – This stage further consists of the following four sub-stages :

a. Proposal Definition

I. Involves mainly the preparation of a request for a proposed application.
II. Proposal mainly helps in the up gradation of an existing application.
III. The application must not be long winding and complex.
IV. The application can be fully justified.
V. The application must be brief and also should be very crisp.
VI. The proposal must consist of the regards, the organizational needs, the organizational support, the required time span and also the proprietary clause.

b. Feasibility Assessment

I. Helps in finding out the extent of the feasibility.
II. Acts as a very important step of the System Development Life Cycle.
III. Helps in the determination of whether the proposed solution is feasible in the nature or achievable, depending on the resources, the problems and the constraints of the organization.
IV. In this step, one is able to make a group of the selection criteria, a selection procedure and also an effective decision making.
V. For having an in-depth analysis of the feasibility, one must keep into notice the following points

A. Technical Feasibility
The various questions that can be asked in this step involves :
a. Can the organization implement the proposed solution with the help of the technology that is present or that is available?
b. Can the solution be implemented with the help of the hardware, the software and the technical resources that are available to the organization?
c. Is the technology that is available to the organization obsolete in the nature or not?
d. Is the technology that is available to the organization intermediate, state of the art or very HiFi in the nature?

B. Economic Feasibility
a. The assessment of the savings to be effected and the cost benefits takes place.
b. Helps in the assessment of the possibility of whether the benefits of the proposed solution would outweigh the costs or not.
c. Helps in the calculation of the tangible and also the intangible benefits.

C. Operational Feasibility
a. Helps in the assessment of the management, the non management and the general positions of the organization.
b. Whether the proposed solution is desirable within the available managerial framework, can also be examined by performing this step in the feasibility assessment phase.

D. Motivational Feasibility
a. The assessment of the degree of the motivation that is used for providing the much needed support to the development and the implementation of the application from the users is done in this step.

E. Schedule Feasibility
a. The degree of the chances of whether the development process of the application can be completed within the stipulated time or not, are assessed.

After performing the Feasibility assessment, one need to prepare the report of the Feasibility and it should be kept in mind that the Feasibility Report must consist of the following points

1. The basic information of the proposal.
2. Highlights as the regards expected costs and the benefits.
3. A gist of the technical, the operational, the motivational and the schedule Feasibility assessment.
4. The expectations linked to the development schedule and the resources that are required.

C. Information Requirement Analysis

a. Very important part of the systems development life cycle.
b. Acts as the base for the whole edifice of the information system.
c. The information objectives of the system can be determined in a very efficient manner.
d. Helps in the determination of the needs of the information when, where, how and who requires that information.
e. Gives vital information about the following

I. Inputs and the outputs data for the reports.
II. Routine and the ad hoc queries.
III. Functional requirements.
IV. Conceptual schema.
V. User interface requirements.

D. Conceptual design

a. Usually called as the logical design.
b. Helps in the establishment of the very clear and the very useroriented design of the application.
c. Helps in the determination of would be – like picture of the system solution.
d. Includes the documenting flow of the various types of the activities and the processing.
e. Gives a detail about the contents of the inputs and also of the outputs.
f. Explains the different functions that are mainly expected to be performed.
g. Includes the general descriptions as regards different manuals.
h. Explains the following up / auditing / controlling of the procedures.

2. Development Stage
The Development Stage forms a very important and a critical and also a resultoriented stage involving further of the following stages

a. Physical System Design – In this step, those activities are performed which help a great deal in the formation of the technical design in detail for the proposed system. With the help of the physical system design, the following can be efficiently specified and also designed

I. The flow of the work.
II. The flow of the user functions.
III. The data communication requirements.
IV. The overall structure of the programs.
V. The security-this point is very much important and also necessary to be taken care of.
VI. The backup points to be taken care of or to be considered.
VII. The quality assurance plan.

b. Physical Database Design – The exiting database and the approach that is followed for the determination of the database requirements acts as a strong base for the physical database design. With the help of the physical database design, the specification of the following can be done in a very efficient manner

I. Logical data relations.
II. Volume.
III. Special requirements.
IV. File organization.
V. The design.
VI. Record specification.

c. The Program Development – The various types of the programming tasks can be explained with the help of the specifications that have arrived at the physical database design phase. And as a result of this, one gets a great help in the development of the program. Now here, it becomes very much necessary to completely have the knowledge about the programming. So the programming can be defined as the process which involves the translation of the specifications formed during the design phase into the program code.
The development of the program is very much necessary as it aims at the coding and then testing the various programs that are needed for the application.

The program development involves a great use of the different types of the techniques mainly for the development of the programs and these techniques generally include the following

I. Modularity
II. Structured programming
III. Applications generators
IV. Application packages

d. Procedure Development
I. Involves the preparation of the manuals, the instruction sheets, the input formats.
II. Can be performed concurrently along with the program development.
III. In the procedure development, the conceptual design and also the physical design are available.
IV. In this step, it is very necessary to take care of the documentation.
V. The need for the development of the procedure is very must for all those, who will be interacting with the application.
VI. The procedures have to be or can be developed for the primary users and also the secondary users of the computer operating personnel.
VII. Training procedures can also be developed and also must be developed for helping in the implementation and then the following up.

3. The Installation and the Operation Stage
This stage acts as the final stage of the system development life cycle and consists of some sub-stages, which can be summarized as the follows

a. The Conversion

I. Involves the activity of the changing from the old system to the new system.
II. The working out of the conversion plan is a must in this stage.
III. For actually conducting a conversion; performing the acceptance testing, file building and the user training is very necessary.
IV. In this sub-stage, use of the different types of the conversion strategies can be done, so having a knowledge about these strategies is very much important and these strategies can be summarized as the follows

A. The Parallel StrategyThis strategy is also called as the parallel run approach. A very crucial point to remember about this type of the strategy is that it is very cautious, very much conservative and most importantly very safe in the nature. This strategy has the ability to work, when the current system and the proposed system run simultaneously till the correctness and the accuracy are tested and also assured.

B. The Direct Cut Over Strategy – In this stage, the replacement of the current system is done with the new system on a cutoff or preappointed day. But this type of the strategy is somewhat risky as compared to the parallel strategy. This type of the strategy is risky in the nature because of the fact that whenever there occurs any type of the problem during the process of the switching over, there is no backup present and hence as a result of this, the degree of the risk involved goes up drastically.

C. The Pilot Strategy- The evolution of the system takes place after its introduction in the section or the department. When the working becomes free from any type of the hassles, then the expansion of the system takes place. After this the installation of the system is done in the whole organization. One critical point that must be kept in mind here is that the installation that is done can be done simultaneously and also in the different steps or the phases.

D. The Phased Approach – In this type of the strategy, the new system can be made applicable functionwise or levelwise. In this type of the approach, firstly the system is brought at the top level, after this at the middle management level and then at last at down the line on the typical ‘back office’ and the ‘front office’ approach.

b. The operations and the maintenance
After the system passes through the conversion step, the next step which follows is of the operations and then of the maintenance. But one very important point to be remembered here is that this process can be performed only when the system is operating without any types of the snags. In this step, once the system is made operational, the estimation about the degree of the chances to meet the predefined goals can be made and this is done by the users and the technical specialists.

During the operation of the application, it is also possible to take a look at the decisions involving the questions like whether any of the revisions or the modifications is warranted or not?

Now comes the turn of the department that is responsible for looking after the maintenance work and this department is generally referred to as the maintenance department. But before going any further, it is very necessary to have a good and a basic understanding of the meaning of the word ‘maintenance’.

Maintenance can be defined as the changes in the hard – ware, the software, the documentation, the procedures to an application system in order to correct the different types of the errors that are present and also to meet the various new requirements and ultimately to improve the efficiency of the processing. Hence, the main duty of this department is mainly to look over the various types of the changes that may occur during the process.

c. Post Audit
The next step after the system is made operational is the step of the post audit and this step of the post audit is very much important to perform as the provision for the post installation review must be available.

The major areas of the concern like the information system quality, the system control, the technical evaluation, the operational evaluation, the economic evaluation, the evaluation of the existing hardware and also the software, the evaluation of the use of the performance monitors and the evaluation of the system logs, can be taken care of in a very good way with the help of the post audit.

With the help of the postaudit, one can in a very proper way, also take care of the post installation review and as a result of this helps in keeping the functioning of the system in a very efficient state.

For taking care of all these things, the audit team is very much responsible and generally consists of the representatives from the users, the system maintenance and the operations etc.

As all of us know, the different types of the languages being used on the computer have not been developed in a one day i.e. it can be said that the evolution of the various languages has taken place constantly over the years and is still taking place. With the passage of the time, new needs are recognized and to fulfill these, the programmers keep on working to find an answer for the various questions and ultimately evolution and the development takes place. Hence because of these processes only, our computers have moved from the first generation to the second generation to the third generation and finally to the fourth generation.

Like this there has been a great evolution with the passing time in the different types of the programming languages.

So the Object Oriented System Development Approach can be defined as the further improvement that takes place over the earlier approaches.

The Procedure Oriented approach
The problem as a sequence of the action that is to be performed was viewed by the ProcedureOriented approach and writing of a list of the instructions for the computer to follow was involved in this approach.
These instructions were organized by the Procedure Oriented approach into the groups and these were referred to as the ‘Functions’.

This approach gives a great emphasis on the following
1. The algorithms.
2. Dividing the large programs into the various smaller programs, as explained above these smaller groups in management information systems are referred to as the ‘Functions’.
3. Global data being shared by the functions.
4. Data moving openly around the system from the function to the function.
5. Top down approach.
6. Transformation of the data from the one form to another by the Functions.

The Object Oriented Programming approach
1. In this approach, the data is considered as the critical element in the program development.
2. The data is not at all allowed to move freely around the system.
3. Data is linked very closely to the functions.
4. A great emphasis is given on the following in the objectoriented programming approach

I. The data.
II. The division of the programs into the objects.
III. Designing of the structures of the data.
IV. Functions operating on the data of an object are tied together in the data structure.
V. The non accessibility of the hidden data by any of the external functions.
VI. The communication of the objects with each other with the help of the functions.
VII. Bottom Up approach in the programming design.
VIII. The addition of the new data and the functions whenever required.

The OOSD Approach
The OOSD Approach involves the combination of the logic of the systems development life cycle and the power of the object oriented modeling and the programming.

The OOSD Approach follows the following steps

1. Identification of the potential problems that may arise within the organization.
2. Knowing the definition of the type of the system that is needed by the users.
3. System designing.
4. Developing the programs for the modules.
5. Evaluation.
6. Periodic review.

The advantages of The OOSD Approach
1. Makes the system design and the implementation very easy.
2. Lots of the development time is saved with the help of The OOSD Approach.
3. Very cost effective.
4. System maintenance is much simpler in the nature.
5. Security of the programs is very good.
6. The various existing modules that have been collected can be used in a number of the applications.

The Object Oriented Languages
The OOSD Approach does not make use of the specific object oriented language but The OOSD Approach and the OOP are sometimes implemented with the help of the extended conventional languages like the C or the Pascal. But generally the OOP is used by the various developers in order to get the structure and also the ease that is provided by the OOP. The categories in which the OOP languages can be divided can be explained as the follows

1. The division is based purely on the features that are supported by these languages.
2. The two categories are –

I. The Object Based Programming languages- Example of this type of the language can be Ada.
II. The object Oriented Programming languages – Examples of this type of the category can include Eiffel, Java, Simula, Small talk etc.

The applications of the OOP
1. Real time systems
2. Simulation
3. Modeling
4. Object oriented databases
5. Hypertext
6. Hypermedia
7. Expert text
8. Artificial intelligence
9. Expert systems
10. Neural networks
11. Decision support systems
12. CAD / CAM systems

Techniques for the assessment of the information requirement are:-

1. Asking Questions –
a. Very commonly used method for the assessment of the information requirement.
b. Involves asking the questions to the persons associated with the use of the system, mainly to get their requirements.
c. Some asking methods can be understood well from the table that follows –

S.NO.	Asking Method	Description	Conditions Suggesting Use
1.	Closed Questions	Every question is consisting of the set of the possible answers that are usually very well defined and from these, the respondent can select.	Analyst is of great need especially when the group of the factual responses is not able to recall the different responses and also the possibilities.
2.	Open Questions	Consists of no answers and the respondent is free for carrying out the formulation of the various types of the responses.	i.        These include such scenarios when the feelings or the views are of great importance. ii.      Also when the respondent is having descent knowledge and also possesses the ability for the formulation of the different responses.
3.	Brain storming	Group method for the elicitation of the various suggestions with the help of the open flow of the ideas.	Helps in the extension of the limits of the spaces of the problems of the various involved participants and elicit the non conventional solutions.
4.	Guided Brainstorming	Various ideal situations are to be defined by the different participants and the most suitable and the best feasible ideal solution is selected.	i.  Plays a very critical role in acting as the guidance for the brainstorming to the ideal solutions. ii.      Acts as a great help for the participants having the system knowledge. iii.    One point very critical in such a scenario is that it may be locked in to the anchoring and the adjustment of the behavior.
5.	Group Consensus	The estimates and the various expectations are obtained from the different participants about the various significant variables. Suitable examples include Delphi Method and the Group Forming.	The best judgmental estimates of the various variables can be obtained but only those variables are included that are very difficult to estimate quantitatively.

2. Deriving from an existing information system
a. The information requirement for any proposed information system can be obtained with the help of the information systems that are in operation currently or also possess any type of the operational history.

b. For the achievement of the above explained point, the use of the various information systems is a must, so now it’s very useful to completely understand the types of the information systems that help play a vital role in such a scenario and the so the various types of the information systems can be summarized as the follows –

A. Existing system to be replaced by the new system.
B. Existing system in another, similar organizations.
C. Information that is available from the hand books, the industry, the specific studies or the different textbooks.

3. Ends Means Analysis
a. Very useful technique.
b. Helps in the determination of the various types of the information needs of the organization at the department and the individual manager’s level.
c. Helps in the separation of the definition of the ends that are generated by the organization process from the means, used for their accomplishment.
d. The outputs from one process acts as the input for the next process.
e. The ends means analysis brings out the critical information needs in a very effective manner.

What are The Critical Success Factors (CSFs)?
a. Act as a small number of the operational goals shaped by the industry and which can be easily identified.
b. Help a great deal in the determination of the information requirements of an organization.
c. These goals generally are assumed to be the assurance of the success for any organization.
d. On the achievement of these goals, the success of the company is almost guaranteed.
e. The critical success factors can be reached with the help of the large number of the methods but very commonly used method is the personal interview method.
f. With the help of the Critical Success Factors, smaller set of the data can be produced, which further can be analyzed but one very important point to kept in mind here is that the data which may be produced may be just aggregated without undergoing any type of the rigor analysis .

Business Systems Planning (BSP)
a. Also generally referred to as the Enterprise Analysis.
b. The Business Systems Planning is a method that is very much dependent or based on the process.
c. Was developed by the IBM in the 1960s.
d. At that time, was usually used for the establishment of the relationship between the large system development projects.
e. The Business Systems Planning is a top down method.
f. This method helps a great deal in the determination of the information requirements and also the information architectures.
g. The Business Systems Planning also plays a very critical role in the identification of the various key entities and the different attributes in the data of the particular organization.
h. The various steps are involved in the process of the Business Systems Planning and these can be summarized as the follows –
I. Achieving the commitment.
II. Proper preparation for the study.
III. Starting the study.
IV. Defining the business processes.
V. Defining the data classes.
VI. Analyzing the current systems support.
VII. Knowing the executive perspective.
VIII. Defining the findings and the various conclusions.
IX. Developing the recommendations and the action plan.
X. Reporting the results.

The Information acts as a very critical tool in making the strategies for an organization by the management of that organization. Information is almost everything for the planning that is to be done for the smooth functioning of the organization. The requirement of the Information can be defined as the statement of the Information that is very detailed in the nature and is usually about the Information needs that a new system has to fulfill. In the Information requirement, it is very important to identify who needs which information and also when, where, when and how it is required. With the conduction of the analysis of the Information requirement, one comes to know about the objectives of the system and after this the detailed description of the functions that the new system is expected to perform can be developed.

The Information is the resource and becomes imperative to analyze and also access the Information requirements of an organization, according to which the suitable information can be provided to the management for doing the planning for the normal and the result oriented running of an organization. With the help of the analysation, one can easily come to know about the needs and the type of the Information that is required.

So it is very difficult and at the same time very much important that the Information needs that are recognized are upto the mark and act suitably at the right time for the management for carrying on further with the process of the planning and then the decision making. In this step, there is generally a large possibility of the results going wrong and hence many system’s analysts refer this step to be very much critical and also at the same time they refer it to be very risky. According to the systems analyst, the major reasons because of whom it becomes very much difficult to get a correct and the complete set of the Information requirements can be summarized as the follows –

1. Humans are largely affected as the Information processors and the problem solvers by the various types of the constraints.
2. The variety of the various types of the Information needs.
3. The complex nature of the various types of the Information needs.
4. The complexity of the different types of the interactions that take place among all the users and the analyst.
5. Sometimes, the users are not ready or do not want to provide the Information about the various requirements.

The requirements of the Information can include the following factors –
1. Economic constraints
2. Technical constraints
3. Time constraints
4. Goals
5. Objectives
6. Procedures
7. Decision processes

The establishment of the various Information requirements can be done at the various levels and this is mainly done for the purpose of the development of the organizational Information system and these levels can be summarized as the follows –

1. Organizational Information Requirements.
2. The database requirements that have been defined by the various data models and various other specifications.
3. The detailed Information requirements for an application.

There is a dire need of understanding these levels in the detail and complete detail about these levels follows –
1. Organizational Level Information Requirement – The Organizational Level Information Requirements can be obtained by performing the following steps –

a. Defining the underlying subsystems :
i. Every organization is observed as a system.
ii. Every system further consists of a large number of the subsystems.
iii. The different subsystems are generally obtained by conducting various discussions of the organizational functions.
iv. The division of the systems in to the various subsystems is very much critical in the nature as with the help of this division the various requirements can be divided and hence, carrying out the whole process by the management becomes much more planned and very simpler in the nature and the working.

b. Developing the manager by the subsystem matrix –
i. The various organizational subsystems are in this step related with the specific managers and this is done with the help of the matrix format.
ii. The matrix is prepared by reviewing the different decision responsibilities of each of the manager, starting from the middle to the top.
iii. One is able to get a good picture of the decision making responsibility with great clarity.
iv. One also gets a very good and a clear picture of the various responsibilities.
v. One is able to recognize all those set of the managers that are to be interviewed relative to each of the sub-system.

c. Define and evaluate the information requirements for the organizational subsystem –
i. In this stage, the groups interviews are conducted of all those managers who possess the decision making responsibility for the various sub-systems.
ii. By performing the above step, the information requirements of each of the sub-system of the organization can be obtained.

2. Database requirements – The applications and the ad hoc queries give rise to the database requirements. The complete architecture for the database forms a major part of the organizational information requirement and helps a lot in meeting the different requirements. A very critical point to remember here is that for getting a very efficient and a detailed database, the requirements must be divided in to defining the data requirement that has been perceived by the different users and also in to defining the requirements for the physical design of the database.

3. Application Level Information Requirement – The information processing for a particular organizational activity or a specific organizational unit can be obtained with the help of the subsystem of the overall information system.

Types of the application level information requirement can be categorized as the follows –

a. Social requirements –
I. Also called as the Behavioral requirements.
II. Are based on the job design.
III. Provides the specification about the various objectives and the assumptions.

b. Technical requirements –
I. Are based on the information that is required for the performance of any type of the task.
II. Provides the specification about the inputs, the outputs, the data that has been stored and the various information processes.
III. The structure and the format of the data are very necessary in case of the technical requirements.
IV. Involve the interface requirements between the user system and the application system.

The Newell Simon Model was proposed by Allele Newell and Herbert Simon and this model mainly focuses on the solving of the human problem and also on the human information system.

According to the Newell Simon Model, the processor, the sensory inputs; the motor output and the three types of the memories (long term memory, short term memory and the external memory) form the very important part of the human information processing system.

In this model, there is no possibility of performing or processing the number of the tasks at a time with the help of the human memory i.e. only one information processing task can be performed at a time with the help of the human memory and this process is generally referred to as the Parallel Processing.

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