While it's not technically the end of the process, the high point in your Enterprise Resource Planning system implementation is when you go live and start using the software to support day-to-day operations. Although numerous variations exist to each approach, there are three essential options for making the transition from testing and preparation to live operation: 'big bang', phased roll-out over time, or parallel operation. Each strategy has benefits and drawbacks, and none of them is empirically right or wrong. Your selection must depend on which appoach fits your company's objectives, resources, and needs.
The Big Bang
After data conversion, essential user training, and conference room pilot testing are complete for all applications and functions, the entire system is activated all at once. This moment typically occurs on a Monday morning after the implementation team has spent the weekend completing file conversions and finalizing software installation. Basically, users sign out of the old system on Friday night and start using new system Monday morning.
- The Benefits: With thorough preparation, this strategy can be quite effective. The transition is quick and clean, and any temptation to revert to old ways of doing things is effectively cut off. Boldly going forward becomes the default option.
- The Drawbacks: There is considerable risk with an all-or-nothing method. There is no going back...despite errors in data conversion, under-trained users, or misaligned functions. Whatever is wrong now must be addressed now. Teams taking this tactic should be prepared for intensive user support and problem-solving during the first few days - or weeks - after going live.
In this case the change-over occurs in phases over an extended period of time, and users transition to the new system through a series of well-controlled steps over a pre-determined spans of time.
- The Benefits: This strategy avoids some of the Big Bang's all-at-once risk by spreading the go-live out over a series of little bangs. Mistakes can still cause disruption, but their impact is usually limited to the specific area being activated. The spacing between the phases allows for time to shore up problems - present and anticipated - before moving on. The project team can focus on resolving issues in limited areas of the business, one or a few at a time.
- The Drawbacks: Operating a company with different parts of the business supported by different systems is difficult, inefficient, and prone to errors. Metaphorically, your business systems will be duct-taped together throughout the go-live period. The custom temporary interface programs between old and new systems that make integration possible are costly, and usually they provide only minimal ties between systems. Users are often asked to enter the same data more than once and reports from either system may be incomplete because the underlying information is split between the two systems. The overall timeline for conversion is generally extended. So while there may be a lower level of risk and stress, a lack of urgency could extend your go-live over a longer, less efficient time.
Here, both the legacy and new system run at the same time for an extended duration. Users learn the new system while working in the old.
- The Benefits: This is probably the lowest risk scenario in terms of possible disruption due to problems with new system functionality. Users can get used to the new system while still having the old, familiar system active to keep the business running as usual.
- The Drawbacks: This approach requires far and away the most time and effort of the three options. Users are essentially expected to do their jobs twice during the duration of the parallel operation. As a result, neither system will get the proper attention. Operations will likely suffer due to overworked people, poorly executed procedures, and confusion over conflicting information coming from the two systems.