"Implementing ERP isn’t just a purchasing decision: it’s committing to redoing how you handle operations. Installing the software is the easy part; adjusting the whole company’s workflow is the most of the work."
Don't think of erp and implementing it as a software development challenge. Sure, Developers can fscrew up*, an erp implementation but they cannot make it succeed - it is fundamentally a business transformation endeavour and must be undertaken as such to have a chance.