1. Parallel Running
Definition: The new system is run alongside the old system for a period of time until confidence in the new system is established.
Pros: Low risk, since the old system is still available as backup; allows thorough comparison of outputs.
Cons: Expensive and resource-intensive, as both systems must be maintained simultaneously; can cause confusion.
Example: A hospital introducing a new electronic medical records system while still keeping paper records until staff adapt.
2. Pilot Running
Definition: The new system is introduced in a small part of the organization first (e.g., one department) before being rolled out to the entire organization.
Pros: Problems can be identified and fixed on a smaller scale; lower overall risk; gradual user training.
Cons: Limited scope at first, so full organizational benefits are delayed; users outside the pilot group may feel left behind; problems may not be exposed as the pilot group is not representative Example: A university testing a new student registration system with just the engineering faculty before extending to all faculties.
3. Phased Running (Phased Implementation)
Definition: The new system is introduced gradually in stages (e.g., by function, module, or region) until the full system replaces the old one.
Pros: Lower risk than direct changeover; costs and workload spread out; users can adapt progressively.
Cons: Can take longer to fully implement; interfaces between old and new systems during the transition may be complex; may not be possible for all systems Example: A bank rolling out a new online banking platform module by module—first payments, then account management, then loans.
4. Direct Changeover
Definition: The old system is completely stopped, and the new system is switched on at a single point in time.
Pros: Fast implementation; lower short-term cost since only one system is maintained.
Cons: High risk—if the new system fails, there is no backup; requires thorough testing and training beforehand.
Example: A retail store moving from a legacy cash register system to a new point-of-sale system overnight.