Irrespective of the specific challenge you are facing, an enterprise software project can roughly be broken down into the following phases. I can do anything from advising on a specific aspect to running the entire process from scoping to implementation for you on the ground.

Problem Statement & Root Cause Analysis
The first and probably most crucial step, skipped by most who argue “we need a system” (rushing straight to step 3) instead of actually spending time mapping out the real problem(s) and root causes of the same. Get clarity on what’s going wrong and how it stops you from execution your mission first.
Requirement Gathering & Goal Setting
You will be working on the wrong things, have people confused, loose focus and spend way more time and money than you need to if you don’t have your requirements down. The deliverable must be a clear list of items, which have been thoroughly challenged, aligned across key stakeholders, prioritized and equipped with a “measure of success”.
Solution Design & Selection
If you have done your homework right, you should be well informed for this most critical phase. It requires you to assess your internal capabilities (functionally and technically), make (long term) decisions over build vs. buy and balance industry best practices and business specific flexibility when selecting systems and modules. If needed (which it will be in all but few cases), you will pick an external implementation parter, who will be instrumental to your success (bad results are most often not due to “the system” but the people implementing it badly). Lastly, you should map out a clear and finite (!) timeline for execution.
Team & Implementation
What I describe here is not necessarily a sequential process, because a clear vision on how you need to staff for implementation (and continuation) is crucial, and should be developed early on. Though many have tried, you cannot implement things like ERPs on the side, but rather need dedicated people to drive this process end to end. Efforts planned across teams – check? Governance structure in place – check?
The actual implementation is an art in itself, requiring (first and foremost) legit project management skills, situational leadership, the ability to constantly mediate and realign stakeholder across the board, ruthless prioritization and execution, as well as the willingness to roll up your sleeves and get your hands dirty. A fair amount of chocolate helps to keep everyone motivated, too. That being said, you will be avoiding the biggest pains during implementation if you did a good job in phase 1-3, since you will be able to execute on clear goals rather than making them up as you go…
Adoption & Change Management
The biggest challenge of any implementation is not getting that inventory integration perfect or automating the weekly P&L – it is people (= creatures of habit). Creating a sense of ownership in your key users needs to be a priority task right from day 1. Only then will they accept, trust and effectively use the new solution (bingo)! Last but not least, you need to think hard about where you want your new system (or its individual modules) to sit within your organization, with regards to post go-live support on ongoing development/continuous improvements (I’ve seen an ERP treated like a bacteria in an organization one too many times). You need to realize that the initial implementation is just the beginning, and you need to be smart about not loosing the momentum after the initial deployment.
