The first step in implementing new system is to determine

Concept

Implementation is the stage of the system life cycle that puts an already designed and already built system into live operation. Nothing about what the system must do is decided at this stage, because that was settled earlier during analysis and design. What implementation planning decides is how the organisation changes over from the existing system to the new one, and that changeover decision is called the conversion strategy, or conversion type.

Applying it to this stem

The stem is scoped to implementing the system, not to selecting it or building it. Once implementation begins, the first thing that must be pinned down is the conversion type, because every later implementation activity hangs on it: the cut-over date, the order in which files and master data are converted, how much parallel running the staff must absorb, how many people are needed on each system, and what the fallback plan is if the new system misbehaves. Fix the conversion type and all of those can be scheduled; leave it open and none of them can be.

The conversion methods to choose between

• Direct, also called plunge or immediate conversion: the old system is switched off and the new one starts on a set date. It is the cheapest, but it leaves no fallback.

• Parallel: both systems run on the same data for a period and their outputs are compared. It is the safest, but the most expensive in staff effort.

• Pilot: the new system goes live in one branch, department or region first, and spreads only after it has proved itself there.

• Phased: the new system is introduced module by module, so each subsystem is stabilised before the next one is added.

Where each of the other choices is settled

So the first step in implementing a new system is to determine the conversion type.