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Implementation Strategies- 5.3.3


Revision Points: (Full course)
Candidates are expected to be able to:
  • describe different systems implementation strategies: direct, phased, pilot or parallel running;

Strategies for implementing new systems:

When a new ICT system has been tested thoroughly by the programmers then it is ready is be implemented into the working environment, replacing the original system. There are four strategies that can be used to do this: direct; phased; pilot or parallel running


Direct implementation:

With this strategy, the changeover is done in one operation, completely replacing the old system in one go.  This usually takes place on a set date, often after a break in production or a holiday period so that time can be used to get the hardware and software for the new system installed without causing too much disruption.

  • Advantages:
    • The most rapid of all the strategies, provided it works!
    • Less risk of confusion between old and new systems.
  • Disadvantages:
    • Most stressful for the users - the old system has gone so there is no going back if they have difficulties.
    • Most difficult to train staff on as the new system was not in place to learn on before the change over.
    • Most stressful for the developers - all the data and files from the old system will have to be converted ready for use on the new one.
    • Most risky - if the new system does not work properly then there is nothing to fall back on.

Phased implementation:

With this strategy, the new brought in in stages (phases).  If each phase is successful then the next phase is started, eventually leading to the final phase when the new system fully replaces the old one.

  • Advantages:
    • Very structured, each phase can be fully evaluated before moving onto the next one.
    • Lower risk, a well planned and controlled introduction of the new system.
    • Easy to train staff by letting them learn new skills on each phase as it is introduced.
  • Disadvantages:
    • Slower than direct implementation.
    • Although each phase is easy to evaluate, you have to wait until all the phases are complete before you can evaluate the whole change over.

Pilot implementation:

With this strategy, the new system replaces the old one in one operation but only on a small scale.  For example it might be tried out in one branch of the company or in one location.  If successful then the pilot is extended until it eventually replaces the old system completely.

  • Advantages:
    • Easy to control, the pilot can be halted at any time.
    • Easy to evaluate because the new and old systems are both running.
    • Low risk, if a small-scale pilot fails then not too much has been lost.
    • Easy to train staff by letting them learn new skills on the pilot system.
  • Disadvantages:
    • It can be slow to get a pilot to completely replace the old system.
    • A pilot may not show up problems that a full-scale implementation would. This is because a system can work well as a small-scale pilot but has difficulties when it is scaled up to a full operating system with more realistic volumes of data to be processed.

Parallel running implementation:

With this strategy, the old and the new system are both used alongside each other, both being able to operate independently. If all goes well, the old system is stopped and new system carries on as the only system.

  •  Advantages:
    • If there are initial problems with the new system then the old one can still be used.
    • Both systems can easily be compared.
    • Easy to train staff by letting them learn new skills on the parallel system.
    • Easy to evaluate because the new and old systems are both running.
  • Disadvantages:
    • Expensive - both systems are being run as fully operating versions so both are doing the same job.  This may mean duplication of staff and hardware.
    • Some risk - there is a greater chance of confusion or errors if the two different systems are being run side-by-side.

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