3.3.5: Implementing computer-based information systems

Installation methods

Aim of this presentation

To help you understand and describe a range of methods for installing a new computer-based system;› Parallel› Phased› Direct› Pilot

Also, to help you to discuss the choice of a particular installation method or methods for a range of applications.

Introduction

Organisations are always looking at updating their technology and systems.

The question is this…

› What is the BEST method of making the transition from the old system to the new one?

Different Methods

The following methods need to be considered when changing a system.

› Parallel implementation› Pilot running› Direct change over› Phased implementation

Parallel

New system run along the old system.

They both run along side each other.

Advantages:› Allows the new system to prove itself before the old one

is taken offline.› Data generated by the new system can be compared to

the old system.› Staff can also be trained on the new system which gives

time for their confidence levels to increase.

Parallel

Disadvantages:› Running the system in parallel means twice as much

work for everyone in the short term. Every time data is entered into one system the same

process must be entered into the other system too.

› Can be costly as you require personal to do double the work.

Pilot

Similar to parallel implementation.

Again, both systems are run in parallel.

With pilot systems only a portion of the new system is run along side the new system.

Pilot

Advantages:› Less of a drain on resources

System Personal

› Cheaper to implement than Parallel

Disadvantages:› Only parts of the system can be compared as not all the

data is input into the new system.› Problems could arise when fully changing over as not all

of the system will have been tested.

Direct Changeover

The old system is stopped and the new system is started.

This usually happens when the system is not being used.

Can happen at the weekend or over night.

Direct Changeover

Advantages:› Cost effective method of implementation as it has the

least strain on resources (assuming all goes well)

Disadvantages› Staff training needs to happen well in advance so they

are fully prepared for the changeover.› If something goes wrong with the new system there is

no fallback.

Phased changeover

Parts of the old system are replaced by the new system.

The old system is used as required.

Parts of the new system are used for training purposes until the next part is ready for implementation.

Phased changeover

Advantages:› If a company has many buildings, the new system

can be installed in one of them. Can run the system in a ‘safe’ environment and on a trial

period. One of the buildings can be used for training purposes

which will allow users to become familiar with the system. Once the system has proven itself in one branch it can be

transferred to all the other branches.

Disadvantages:› Takes a long time to fully implement as it has a lot

of stages.

Questions – Q1

A supermarket chain has recently had a system upgrade commissioned. The software is ready for use but has not yet been tested. The chain has many branches across the country.

What is the best method for the system to be implemented. Explain what your method involves and why you think it is the best method.

Questions – Q2

A small software company has recently upgraded their system. It was designed and tested in house and they know the system works.

What is the best method for the system to be implemented. Explain what your method involves and why you think it is the best method.

Questions – Q3

A large company houses lots of networks over different sites. The company use different types of computer for different jobs e.g. they use Apple Mac for designing graphical products and PCs for admin and office work. They want to upgrade some of their systems but are worried about software and hardware incompatibilities.

What is the best method for the system to be implemented. Explain what your method involves and why you think it is the best method.

Questions – Q4

A school wants to upgrade its current computing facilities. It has four dedicated computer rooms and one mobile facility. They are on a limited budget but do need to upgrade their computers. Some rooms were updated more recently than others.

What is the best method for the system to be implemented. Explain what your method involves and why you think it is the best method.