It might seem odd for a consulting firm to publish a buyer’s guide for hiring consultants. But bad engagements hurt everyone in this profession — most of all the clients who conclude process improvement “doesn’t work here.” So here are the five filters we’d apply to anyone, including us.
1. Master-level certification — not a weekend belt
Certifications vary wildly. A CSSBB (Certified Six Sigma Black Belt) from a rigorous body represents applied projects and examined knowledge; a CSSMBB (Master Black Belt) adds years of leading programs and developing other practitioners. A certificate from a two-day course represents attendance. Ask which one you’re buying — and ask to see the projects behind it, because the belt matters less than what it was earned on.
2. Documented results in dollars, not slideware
Every consultant has case studies. Ask for the numbers behind them: baseline, result, how it was measured, and whether finance signed off on the impact. “Improved efficiency by 30%” is a sentence; “$1.4M annualized, validated against the baseline by the controller” is a result. Firms with real results love this question. Firms without them change the subject.
3. Experience with your industry’s constraints
The method is universal; the constraints are not. Process improvement in a regulated bank — where every change touches compliance and audit — is a different sport from a machine shop. Healthcare has clinical governance; higher education has shared governance; law firms have partner economics. Ask specifically: what do you know about our constraints, and where have you worked inside them?
4. Capability transfer, not dependency
The engagement should end with your team able to do this work without the consultant. That means training and coaching are built into the plan, your people co-lead projects from day one, and the tools stay when the consultant leaves. If the commercial model only works when they never leave, that’s not transformation — that’s a subscription.
5. The willingness to say “you’re not ready yet”
This is the filter that predicts all the others. A consultant who will take your money before your organization can absorb the work is optimizing for their revenue, not your results. In the first conversation, pay attention to whether they probe your readiness — sponsorship, data, capacity — or just your budget.
The best consultants work themselves out of the job — on purpose. Hire outcomes. Not slideware.
Questions to ask in the first meeting
- Walk me through one project that failed. What did you learn? (No failures = no honesty.)
- What would make you tell us not to start yet?
- Who on our team will be able to lead a project without you in six months, and how?
- Show me a control plan from a past engagement. (This reveals whether their improvements are built to stick.)
And before any first meeting — ours included — get your own picture of where you stand. The free toolkit below includes the readiness and cost calculators that make you a sharper buyer.
Frequently asked questions
What does a Lean Six Sigma consultant cost?
Models vary: project-based fees, monthly advisory retainers, or day rates. More useful than the rate is the ratio — a well-scoped first project should have a credible path to returns that are a multiple of its cost, validated against a baseline. If a consultant can’t explain how the engagement pays for itself, keep interviewing.
Do we need a consultant at all, or should we train internal belts?
Both paths work, and the best answer is usually sequenced: outside help to establish the method, deliver early wins, and train your first practitioners — then a deliberate handoff to internal capability. Be wary of any proposal with no handoff in it.
Become a sharper buyer first
Run the free Readiness Blueprint and Cost of Poor Quality Calculator before you interview anyone — including us. You’ll know your gaps and your number, and you’ll hear the difference in every answer.
Prefer a conversation? Let’s talk — 610-316-4056.