Question

Q-Identify, diagram and discuss implementation alternatives of Systems Development Life Cycle (SDLC) system ?

Direct

phase

parlallel

Could you please explain these alternatives deepely and clearly by using own words and draw its digram

Answer 1

Direct Changeover Method of System Development:

In the Direct Changeover method also called the Big Bang adoption the entire existing system and everybody associated with the new system is shifted to a new system and its working methodologies on a given date. On this given date the new system becomes functional and the old system is abolished. This is a common and simplest form of system changeover which is practiced when the entire system is not very complex and the adaptability of people to the new system is need seen as a big challenge. In a direct change over everybody uses the new system and the older system will not be used any further.

The process flow of the implementation of Direct Changeover system requires a lot of background work before hand as there is not enough scope of flexibility when the new system is adopted and the training needs of the people also needs to be fulfilled in advance. In case of big complex systems the Direct Changeover approach is riskier.

The flow of the process to implement a direct changeover is illustrated hereunder in a step by stem manner to understand it further:

Stages in implementation of direct changeover

The implementation can be represented as illustrated here under by the diagram:

Advantages of Direct Changeover:

• It allows to change the system when it is most convenient time as may be chosen by the management.
• The cost implications of this method is cheap from other alternatives, provided the implementation and adoptions go well.
• There is no data duplicities in this case as the previous system and data is abolished. Only useful data is carried forward in the new system.

Disadvantages of Direct Changeover:

• The main challenge is that the staff has very little time to get trained and adopt to the new system as the change is instantaneous.
• There is no roll back option in this case and the new system has to be followed. No plan B in case of difficulties.
• There is a time in the roll out process in which neither of the systems are functional.

Phased Changeover:

This method is comprise between the direct and parallel change over as in this method the change is implemented in various phases. The new system is implemented in one stage at a time. In this model the strategy is to allow the new system to slowly overtake the older system in stages so that the total system is not abolished at once rather the modules of the old system are replaced in a staged manner.

In this process the existing system keep operational till the time all modules are not replaced by the new system. This gives the users time to acquire the understanding of the working procedures and to adopt while being able to access the old system for a while.

The same could be understood from the following diagram:

Advantages of Phased Changeover:

• Users gain experience and knowledge of the new system which improved their overall understanding of the new system.
• In case certain issues arise it affects any single stage of implementation rather than the whole system.
• The adoption process is slow and steady unlike the Direct Changeover model.
• The IT team can implement the model in least cumbersome manner as bug fixing is stages wise unlike in other models.
• The initial phases increase the ability of IT implementation team of the organizational dynamics and helps it to better develop the system to suite unique organizational requirements.

Disadvantages of Phased Changeover:

• The stage wise implementation results in long duration of project and the cost involved.
• Some interconnected process would be requiring other stages to finish in order to become fully functional.
• The need for urgency and focus may be lost during the stage wise implementation sometimes.

Parallel Run or changeover:

In the parallel changeover the new system runs parallel to the old system for a decided period of time by the management. This means that a separate standalone system is prepared which is then allowed to be used by the users when the old system is also functional. This the most popular method as it allows the flexibility to learn and adopt to the new system and also not hamper productivity by keeping the old system running for a fixed duration till the management decides.

The bug fixing and integration of data and resources with the new system is also fail resistant owing to the live user testing and the IT team working on improving the performance of the system in the background. This method is also attributed with the lowest risky among available options.

Advantages of Parallel Changeover:

• Least risky as the new system assumes the roles of the old system as the old system is operational simultaneously.
• Users learn the new system keeping the legacy system functional thus not hampering the day to day activities of organization.
• There is always a fall back available in the form of the old system in case the new system does not fit the requirements.

Disadvantages of the Parallel Changeover:

• This is an expensive method where the user has to maintain two resources for keeping both the systems operational.
• The employees may be aggrieved as they have to do duplicate entries on both the systems to make it work.
• The level of effort required to accomplish the task becomes huge from the management as well as executive committees.