In my experience from consulting for various B2B clients, when auditing for improvements in clients relationship marketing practices it's key to isolate Process & Flows, Systems & People in blocks.
Process & Flows refers to the client's campaign planning process, campaign flows designed to acquire, qualify, funnel, close & nurture prospects and measurement practices. The idea will be to then develop ideal process, flows & measurements, and pare them back based on what's feasible and what's immediately required. Since they have been pared back rather than added to, it's easy to scale for complexity and integrate testing seamlessly.
Systems Audit will comprise marketing databases, marketing infrastructure, marketing automation and lead management systems at the very least. In my experience, there's very little impact a consultant can make in this area for established practices. This is best done when the Process & Flows have been streamlined and they help identify system deficiencies to build a strong case for modifications/additions. Or when organisations are setting up this practice from scratch
People Audit is designed to identify resourcing & proficiency. This is a low hanging win, usually addressed quickly through outsourcing, in-sourcing, hires, workshops & training.
Also, best to have the owner of this practice brief and then deep-dive with key stakeholders to gather requirements, before designing the ideals & recommendations for all of the above.
This is a simplistic view based on years of experience and has worked for me. I'd like to hear your views & experiences to always improve it any day.