the phrases ‘big bang’ and ‘stages’ are used to describe methods to introduce a new system of organization. A ‘big bang’ ERP implementation is most often used to describe the go-live or cutover scenario where companies switch from the old ERP their systems to their new system at one point. In contrast, a “phased” approach describes a scenario in which components or modules of ERP systems are presented in an organized, replacing the old system gradually.
Many factors need to be considered when deciding on the Go- live policy. For example:
- is performed cover a single page or multiple pages? Big Bang implementation of one page is considerably easier to manage than the big bang simultaneously in many places. However interdependencies between sites might dictate that a phased approach is not viable.
- is performed achieve one company or more companies? If multiple entities involved then it might make sense to phase the implementation by trading company or business unit.
- If stages because what this will mean for integration between new systems and legacy systems during the period? This is possibly one of the most problematic areas for the phased model. If you introduce a new system in a phased manner then you have to work out how the new system and the old system will work together for a period of time. This may include creating a bond that would not be necessary if all units were introduced at a time, as well as creating user documentation and standard operating procedures (SOPs) that cover how business processes work in the coming term.
- Are there any other competing activities that need to be taken into account? Factors such as regulatory compliance, acquisitions, new product introduction and other capital expenditure programs may affect the required deadline ERP implementation.
- What risk is acceptable? The general inspectors is big bang implementations are inherently more risk. This is because the integrated nature of ERP system means that a failure in one part of the system can have knock-on effects elsewhere. The scope of the Big Bang execution can also mean the full end-to-end system test is difficult to achieve, and it is only when the system goes live to all interdependencies are fully tested.
- which costs more – big bang or gradual? phased implementations usually take longer to fully complete; this usually means more time from both the ERP vendor and the project team and the increased costs. The additional time and costs have to be weighed against some of the main arguments used against the big bang approach, such as the company’s ability to deal with a huge amount of change going on all at once and the increased risk of failure. Temporary interface between new systems and legacy systems can also increase costs in a phased approach.
Both methods have advantages and disadvantages. However, it is important to point out that the implementation strategy need not be limited to these two options. Sometimes big bang approach can be used to implement a ‘must have’ functionality within the core ERP modules, followed by a phased implementation of the ‘nice to have’ functionality and implementation of non-core modules such as document management, business intelligence, and maintenance management
For more information on ERP, check out :. http://bsm.ie/practices/erp-life-cycle-management