The implementation of Enterprise Resource Planning systems (ERP)

If you were the CIO of a large enterprise and the rollout and implementation of an ERP system was going badly, where would you begin to try to determine what was causing the difficulties that are being encountered in the project? Would you bring in an outside consultant or rely on in-house talent to track down the causes for the less-than-optimal outcomes? Why would you choose one asset over the other? Conduct research on the topic and answer the following question by providing facts that support your position