Most of failure of ERP systems have taken place due to improper implementation. Let us look at what are the essential six phases of any ERP implementation. In the Big Bang approach, the different stages of implementation are done serially and then in a big bang it is brought in line in a short period of time. This implementation process is very risky.
Organisations frequently go for the iterative approach where the implementation is done phase by phase with important departments in the organisation. The transition is slow and incremental. The advantage of this approach is that the errors in the implementation (inevitably there will be many) are progressively discovered and attended to, one at a time, so that the system does give a surprise to the organisation and keeps serving the basic interests of the customer and organisation and other stakeholders on a limited scale initially and then maturing to an advanced state later on.
ICMR case on ERP Failure at HP ..