Big bang adoption is a hardware or software migration method that involves getting rid of the existing system and transferring all users to the new system simultaneously.
Implementation is faster with big bang adoption than other methods, such as parallel adoption, phased adoption and pilot conversions. Because the old system is no longer available, users can’t put off learning the new system. Furthermore, the complete and simultaneous implementation also avoids issues that can arise when users are working with different software or hardware. Big bang adoption is the least expensive migration method, assuming there are no major problems.
On the negative side, however, it can be hard on users to have to learn the new system immediately. The method also involves a lot of risk – problems that arise during implementation can be unpredictable, plentiful and serious, and fallback systems may be inadequate to deal with them. However, if the two systems are incompatible, big bang adoption may be the only viable method.
The big bang adoption method is also known as the direct conversion, plunge, slam dunk or cold-turkey method.