There are three most common approaches to adopting ERP systems.
1. Big bang (Single-step method). Moving business processes into an ERP system happens within a day. A specific date of ERP introduction is set up and from then on, all employees and departments start using the new software. Using the big bang approach, the enterprise can start enjoying automation in the fastest possible way, however, employees will need time to get used to the functionality and learn working with it so their productivity may lower for a while. Risks have to be carefully considered when choosing this ERP implementation method.
2. Rolling out in phases. ERP features are introduced gradually. It takes from a few weeks to months until full implementation of the ERP system. With this measured approach there is practically no risk of productivity drop, as in the case of the big bang method. Still, phased rollout is not all rosy. Firstly, it will take a while until the system is fully adopted, and secondly, two systems have to be supported at a time: the one adopted, which is in fact a cut version of the full one, and essentially the full one.
3. Parallel adoption. With this approach, the new system is used along with the old usual one (applicable if you’ve been using an out-of-the-box ERP system and are switching to a custom written solution). It’s considered the most risk-free as all data is recoverable in case something goes wrong with the new ERP, but the odds of human error grow higher because the same data has to be entered twice manually.