Corrective maintenance: It is performed to fix errors.

Adaptive maintenance: It adds new capability and enhancements.

Perfective maintenance: It is used to improve efficiency of the system.

Preventive maintenance: It reduces the possibility of future system failure.

Corrective maiantenance:

In CHIS if there is any problem such as incorrect report or inconsistent data then a user can submit a system request with supporting evidence. These errors occur because the system developers did not test for certain data combinations or processing situations.  In this situation corrective maintenance diagnoses and corrects error in an operational system but it also requires careful analysis before making changes. We can use a standard procedure for minor errors, such as incorrect report title or an improper format for data element. In this procedure If a user submits system request then it will be evaluated, prioritized, and scheduled by the system administrator or the system review committee and if the system request approved then the maintenance team will design, test, documentand implement a solution. If an emergency occurs, the maintenance team will bypass the initial steps and tries to correct the failure immedeatily.And in the mean time a written systems request will be prepared by a user and add to the maintenance log, so that when the system again becomes operational the maintenance team will determine the cause, analyze the problem and will design a permanent solution.

Adaptive maintenance:

Adaptive maintenance occurs in response to user requests for improvements to meet changes in the business or operating environments. There need for adaptive maintenance arises from organization’s environment changes such as new services, new technology, support for a new web based operation.  In CHIS we can use the adaptive maintenance because we are switching from one system to another. The procedure for minor adaptive maintenance is similar routine corrective maintenance. In adaptive maintenance also a  user will submit systems request that is evaluated and prioritized by the system review committee. A maintenance team then analyzes, designs.tests, and implements the enhancement. Although the procedures for both the corrective and adaptive maintenance are same ,adaptive maintenance requires more IT department resources than minor corrective maintenance.So,it can be said that no doubt it will solve the problems but this maintenance can prove very difficult  because it will require more resources and the enhancement will be required to work with in the constraints of the existing system.

Perfective maintenance:

The IT staff usually initiates the perfective maintenance projects to improve performance and maintainability. In  case of CHIS during  system operation ,changes in user activity or new data patterns can cause a decline in efficiency of the system, and that time perfective maintenance will be needed to when users will be concerned about the performance then perfective maintenance could improve response time and system efficiency. This maintenance can improve the system reliability by modifying the data entry process .It can highlight errors and notify the users that they must enter proper data. But in organizations with limited resources often go for new system development, adaptive maintenance and corrective maintenance more important than perfective maintenance.

Preventive maintenance:

To avoid problems, preventive maintenance requires analysis of areas where trouble is likely to occur. Preventive maintenance often results in increased user a satisfaction, decreased down time, and reduced TCO. Like perfective maintenance, the IT department normally takes the initiates the preventive maintenance.

The process of putting the new system and retiring the old system is called system change over process. There are four methods of changing the systems.

1. Direct Cutover: Direct Cutover is the method in which the old system stops  and the new system starts simultaneously.
2. Parallel: With parallel operation, users operate both the old and new information systems for some period of time.
3. Pilot – With pilot operation, a specified group with in the organization uses the new system for period of time, while the old system continues to operate  for the rest of the users .After system proves successful at the pilot site it is implemented through out the organization.

        4.   Phased: With phased operation, you implement the system in organization, but only module at a time, until the entire system is operation.

The recommendation is for the phased change over because it will be the more appropriate approach in the case of health centers. A direct cut over and pilot approach can also serve the purpose, but we can not think of parallel approach, because it is the most costly system change over method .No doubt it involves the least risk but it can not be implemented in health center because Health Centers can not afford the maintenance of both the old and new systems.

Direct Cutover:

Although initial implementation problems are a concern with all four methods, but these problems are more significant in case of direct cutover method. Minor errors are very difficult to detect in this method because the new system has replaced the old system and therefore it is not possible to compare the outputs from both the systems. But in the case of health center activities are being performed manually and it can be better option to adopt a technology based system. Direct cutover may be one of the choices, because both the systems are incompatible. A direct cutover if done correctly can be the cheapest in terms of minimizing duplication. If Health Centers adopt this method then it will not be difficult for them to roll back to the manual system if the users find any problem with the new system, which is not possible in the case of direct cutover method.

Parallel operation:

The most obvious advantage of parallel operation is lower risk .in addition to this it will also give the chance organization to use the old system as back up if the new system is not working at the desired level ,which is not possible in the case of Direct cutover method.

But this change over method is the most costly to be implemented because an organization will have to pay for both the systems during the parallel period. It can not be implemented in Health centers because it requires all the aspects of the system to be developed before the system is used, and in Health Centers there is no accurate system for any department. In addition to this it will need more employees to handle extra workload, that will no doubt create extra financial burden on the organization.

Pilot Operation:

A pilot operation can be one of the choices because it can be implemented at  a selected location of the health centers .A new system can be installed in one department of health centers. We can see the performance of system in one department and if it proves successful at the pilot site, it can be important in the rest of organization.  This operation method reduces the risk of complete system failure as compared with a direct cut over method. It will be less expensive for a health center. Besides this it will shorten the changeover period if later we use parallel approach to complete implementation.

Phase operation:

It seems to be possible to implement the new system in stages or modules. Each of the system can be implemented by using any of three changeover methods. One advantage of a phase operation restricted to the implemented module only. For example, if a new subsystem fails to operate properly ins any of the health centers, the failure of the system will not affect other systems. It is less expensive than parallel operation because we have to work with only one part of the system.

A system development methodology refers to the frame work that is used to structure, plan, and control the process of developing an information system. A wide variety of such frame works have evolved over the years but in recent years, there has been a surge of interest in object – oriented methodology in the analysis and design of a system. However there is dilemma as how best fit the OO topics with the existing coherent discussion of structured approach of developing a system. Now we are going to address some issues related to the two design paradigms. The systems development life cycle can be defined as a process of understanding how an information system can support business needs   or requirements of an organization, modeling the business processes, designing the systems components, and building the system. A system development project thus goes through a sequence of four fundamental phases: planning, analysis, design, and implementation. Each of these phases also consists of a series of steps or activities that rely on some techniques to produce required deliverables. Even though both structured and object oriented methodology follow common phases or activities, but how they are approached by the system development group can be different –the project team might move through the phases and steps logically,consecutively,incrementally, or iteratively.

The most common approach to SDLC is a structured methodology that is based on waterfall model. It adopts a formal step by step approach to the SDLC phases and

activities-the activities of one phase must be completed before moving to the next phase. At the completion of each activity or phase, a document is produced that must be approved by the stake holders before moving to the next activity or phase. The centre of the structured approach is the process model that depicts the business processes of a system, and tool used to present this model is the (data flow diagram) DFD.The DFDs and their associated data dictionary contain information about the systems components that need to be designed and ultimately built

Another approach to SDLC is Object –Oriented methodology. It follows an iterative and incremental approach to system development. The systems development life cycle is viewed as consisting of several increment phases: inception, elaboration, construction, and transition. In each increment or phase, the developers move through the activities of gathering requirements, analyzing the requirements, designing the system, implementing the design, and testing the system. Thus the phases of the traditional systems development approach do not match with those of the OO life cycle; but in each increment, all phases of the traditional life cycle (requirements, analysis, design, implementation, testing) are visited iteratively until the developers are satisfied. So we can say that in both the systems steps to develop a system do not change but how these steps are performed can be different.

The object oriented approach uses a set of diagramming techniques known as the Unified Modeling Language or UML. It focuses on the three architectural views of system: functional, static, and dynamic .The functional view describes the external behavior of the system from the perspective of the user. The static view is described in term of attributes, methods, classes, relationships and messages. The dynamic view is represented by sequence diagrams, collaboration diagrama,and statecharts.All diagrams are refined iteratively until the requirements of the information system is fully understood .Finally ,the information system is developed through the combination of traditional relational database and object-oriented programming-rather than true object-oriented methodology for both programming and database.

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             The step of developing a system (planning-analysis-design-implementation) remains same in both the methodology but the approach of system development team can be different. The structured approach tries to understand a problem using model termed Data-Flow Diagram (DFD), while the object oriented approach uses Use Cases. In the structured approach, design of all system components (input, output, program modules files and database) are evolved from DFD, while in the UML approach, there are many models to deal with and there are no clear-cut steps such that the design of the system components evolves logically from a single model.                          

              While the structured approach provides clear-cut steps(planning-analysis-design-implementation) from the beginning to the end of the systems development life cycle, the object-oriented approach does not-there is no clear-cut step in moving from analysis to design iterative and incremental nature of object oriented approach refers to continuous testing and refinement of the system throughout the project lifecycle. The same UML diagramming techniques are used throughout all phases of the SDLC, although some diagrams are more important in some phases than the others. As the developers move through theSDLC, the diagrams gradually become more detailed, blurring the separation between the analysis and design phases. Understanding the continuous analysis of a problem through Use Case is fine, but when it comes to design, it becomes very complex. Moving from design to implementation further complicates the matter. Why should we talk about the class model at the beginning of the analysis phase and then discuss about the relational database in the implementation phase-why not implement the system in an object oriented database? So it can be said UML is nothing more than a notation-it does not dictate any specific approach to developing information systems. Even though it is unlikely, it is possible to develop an information system using a traditional approach, such as structured systems development, and to document the analysis and design using the UML.This reflects the intricacies of using true OO methodology in developing an information system.

Process Name:Verify Order

Description:

The purpose of the proces is to to verify the order given by the  customer. It determines whether a customer’s order should be accepted based on the customers credit standing and the availibility of the ordered DVD.

Process number:- The number of the process is 1.0

Process Description :

Input data flows :- 1.Order :- To check the detail of given order

                               2. DVD detail:- To check the availibility of the DVD

Output data flow:- 1. Accepted order

                               2. Rejected order

Structured analysis is a trdaitional system development technique that is time tested and easy to understand. Wecan use different techniques to answer to explain the structured analysis.

Document Review:

This technique can be used in this because system analyst can use their system as mainframe system to create many different types of images and diagrams.Moreover system analysis is totally based on detailed planning.

Observation:

In structured analysis observation can be used to observe all steps in a transaction and note the document,inputs,outputs and all the process involved.

Questionnaires and surveys:

Questionnaires and surveys can not be used in structured analysis because we cannot send information from one object to another object and without any commmunication we cannot do any sort of questionnaires and surveys.

Sampling and Research:

We can use sampling and research in stuctured analysis because it uses series of phases to plan, analyze,design,implement and support an informationsystem. So on behalf of above statement we can say thatsampling and research can be done.

Ques:What is the Object oriented approach to systems development?

Object Oriented analysis is the newer approach that many system analysts prefer to use.In this also we can use different techniques.

Document Review:

Document Review can be done in this case because object oriented analysis follow the inheritence law,means we can easily review our document from lower inherited class to upper inherited class.

Observation:

In object oriented analysis we can use observation because it follows the rule of inheritence that gives us a chance to observe all the steps.

Questionnnaire and surveys:

This technique can be used here because in ths analysis we can send information from one object to another object as message and we can get reply from another object;so in ths case we can easily commmunicate and can do questionnnaires and surveys.

Sampling and Research;

Sampling and Research can be uused here to determine how one object affects another objects.For example to support a bussiness process,a system developer can design reusable components that llow faster system implementation and decreased development cost.

The main problem with CHIS is that there is no information  system at present to capture and store health data.Unavailibility of accurate records on the number of children who have been immunized and type of vaccines they have received multiplies the problem .Besides there is no system for tracking children’s weights so that under weight cildren can be monitored and no consistent record of what diseases a child might have inn the had in the past

Que2 What information do you need to find out about the child health information system to develop a detail understanding of current system.

Ans. This project is required because department of health needs an infomation system which should be accessible at all centres so that information about the child may be viewed and updated from any health centre. The information that is mandatory to develop CHIS for detailed understanding includes accurate health data on children. Besides this, to develop this system we also need health care information, child information, child vaccination information and child medical visit information.