I've learned a few things about managing this transition. They're not complicated, but they require discipline.
First, knowledge transfer isn't a week-long activity at the end. It needs to happen continuously from day one. Internal team members should be co-leading workshops, co-authoring deliverables, co-presenting to steering committees. They should be visible, not just supportive.
Second, documentation matters less than relationships. The internal team needs to own the relationships with vendors, with regulators, with key stakeholders before the consultants leave. They should be the ones having the difficult conversations, not just sitting in on them.
Third, governance can't depend on external reporting. If the program's only real accountability mechanism is the steering committee run by consultants, it will collapse when they're gone. Build internal governance that works without them — clear decision rights, regular performance monitoring, real consequences for missed milestones.
Fourth, accept that some things will break. The transition is never seamless. The question is whether the team can identify problems quickly and fix them without waiting for someone to fly back in. That means having a real issue escalation process, not just a risk register that gets updated monthly.
Fifth, plan for the emotional transition. Eighteen months of consulting support creates dependency. When it's gone, there's a psychological drop. The team feels exposed. Acknowledge that, talk about it, and build in extra support for the first few months.