What are the limitations of using ERP system in an organization?

Each good system like ERP has some limitations and for these limitations, sometime people become reluctant to implement good system. The limitations which are associated with an ERP system are given below: Difficult to implement in running businesses Often requirement of Customization which is problematic ERP deployments are time consuming, projects may take 1 to 3 years Policy Limitations Ongoing Support Lack of user participation in ERP implementation Problem of Harmonization in ERP processes with the business processes Resistance to Change High Annual Charges Cutting Expenses on Training Dependency on Vendor/High Switching Cost Cost savings / ROI may take years to realise