Parallel Adoption - Evaluation / Practical Relevance

Evaluation / Practical Relevance

There are several lessons that can be learned from case studies: The Nevada DMV system case, described by Lee (2004), learns that an implementation to a new process can also have a political implication. When the system that will be changed affects the general public and it is not only an internal system that is being changed, there are some more pressures that influence the organization. In this case, concepts as company image and reputation can drastically change if customers are faced with more delays in for example communication or ordering goods. It is suggested that if the system is politically sensitive, more attention should be paid to the conversion method and preferably parallel adoption is opted, since there is less risk involved.

A series of lessons learned from a number of actual case scenario’s implementing a new portfolio system, performed by a business-consultancy firm (Venture, 2004) show some interesting lessons learned from the field. they seem to fit perfectly with the issues mentioned for a generic parallel adoption process, based on a combination of scientific work. To summarise:

• Risk assessment and contingency (workaround) planning is very important
• Assign project team roles
• Construct specific milestones (like PRINCE2) that include training and testing plans
• Identify potential risks and execute your contingency plan when necessary
• Communicate project status
• Changes should be appropriately authorized
• The conversion strategy needs to carefully examine the data requirements
• New and changed data should be tested against validation rules
• Construct a thorough rollback plan
• When possible, negotiate a pilot conversion

There are also at least two difficulties with parallel conversion that may make its use impractical in the 21st century, though it was a staple of industry practice when inputs consisted of decks of punched cards or reels of tape. These are:

1. It is impractical to expect end users, be they customers, production line workers or nearly anyone else, to enter every transaction twice via different interfaces.

2. Timing differences between two multi-user interactive systems can properly produce different results even when both systems are operating correctly, are internally consistent, and could be used successfully by themselves.

As a result, parallel conversion is restricted to a few specific situations today, such as accounting systems where absolute verifiability of results is mandatory, where users are all internal to the organization and understand this requirement, and where the order of activities cannot be allowed to affect the output. In practice, the pilot and phased conversion methods are more relevant today.