How do I hire a Six Sigma consultant to improve our manufacturing processes?

To hire a Six Sigma consultant for your manufacturing plant, you must define your operational goals, verify proper certifications (like Black Belt), and evaluate their industry-specific track record.

Steps to Hire a Six Sigma Consultant

- Know what problems you need to solve, such as high scrap rates, slow cycle times, or bottlenecked assembly lines.
- Set clear performance targets for the project.[](https://manexconsulting.com/blog/how-to-choose-the-best-lean-six-sigma-consultant/) [[1]](https://manexconsulting.com/blog/how-to-choose-the-best-lean-six-sigma-consultant/)

- Look for a **Certified Lean Six Sigma Black Belt** or **Master Black Belt** credential.
- Check if they have direct experience in your specific manufacturing sector (e.g., automotive, electronics, food processing) so they understand your regulatory and operational environment.[](https://manexconsulting.com/blog/how-to-choose-the-best-lean-six-sigma-consultant/) [[1]](https://manexconsulting.com/blog/how-to-choose-the-best-lean-six-sigma-consultant/)

- Ask for past project examples showing measurable financial or efficiency gains (like throughput increases).
- Contact past manufacturing clients to ask about the consultant's communication and change management skills.[](https://manexconsulting.com/blog/how-to-choose-the-best-lean-six-sigma-consultant/) [[1]](https://manexconsulting.com/blog/how-to-choose-the-best-lean-six-sigma-consultant/)

- Ensure the consultant communicates clearly and can train your internal staff effectively.
- Ask how they handle worker resistance on the factory floor.[](https://www.ziprecruiter.com/Jobs/Lean-Six-Sigma-Consultant) [[1]](https://www.ziprecruiter.com/Jobs/Lean-Six-Sigma-Consultant)[[2]](https://manexconsulting.com/blog/how-to-choose-the-best-lean-six-sigma-consultant/)[[3]](https://tallyfy.com/six-sigma-consultant/)

- Choose between a fixed-price project scope, a retainer, or an hourly coaching model.
- Establish milestones linked to data-driven deliverables using frameworks like [DMAIC](https://asq.org/quality-resources/dmaic) (Define, Measure, Analyze, Improve, Control).[](https://www.reddit.com/r/consulting/comments/1l9qbp8/is_six_sigma_still_worth_it_for_consultants_what/) [[1]](https://www.reddit.com/r/consulting/comments/1l9qbp8/is_six_sigma_still_worth_it_for_consultants_what/)

If you'd like, I can:

Help you write a job description or request for proposal (RFP) List specific interview questions to ask candidates Explain the difference between Green Belts and Black Belts for your team

If your goal is measurable improvement in a manufacturing plant, I’d hire a consultant based on demonstrated project results—not simply on having a “Six Sigma Black Belt” certificate. ASQ specifically recommends testing candidates on completed projects and their ability to reason through real process problems.

A practical hiring process

1. Define the business problem first Write down 1–3 measurable problems, such as:

• Scrap/rework is 8% and needs to reach 4%.
• OEE is 62% and needs to reach 75%.
• Changeovers average 90 minutes and need to reach 45 minutes.
• Customer defects are 3,000 ppm and need to fall below 1,000 ppm.

This gives the consultant something concrete to attack and makes proposals comparable. 2. Look for manufacturing-specific experience

Prioritize someone who has actually improved processes similar to yours—ideally your industry, equipment type, production volume, and regulatory environment. A consultant who understands automotive, aerospace, medical devices, food, electronics, etc. will generally bring useful domain knowledge in addition to the Six Sigma methodology. The American Society for Quality (ASQ) 3. Source 3–5 candidates

Two good starting points are:

• asq.org — ASQ's network for finding quality and process-excellence experts.
• iassc.org — useful for understanding Lean Six Sigma credentials and finding accredited providers.

You can also get referrals from manufacturing associations, equipment suppliers, peer plants, and your local ASQ community. 4. Verify credentials—but don't stop there

A Black Belt credential is a useful screening signal. ASQ, for example, offers Six Sigma Black Belt (CSSBB) and Green Belt (CSSGB) certifications, and its certification registry can be used to verify certifications.

More important, ask each candidate for 2–3 completed projects and request:

• Starting and ending performance
• Financial impact
• Project duration
• Their personal role
• Tools/methods used
• How the improvement was sustained
• A reference who can verify the results

5. Give them a real manufacturing case during the interview

For example:

“Our first-pass yield has fallen from 96% to 89%. Defects are concentrated on two shifts but we don't know why. Walk us through what you would do during your first 30 days.” A strong consultant should naturally discuss Define → Measure → Analyze → Improve → Control (DMAIC), data collection, measurement-system validation, root-cause analysis, experiments, process controls, and operator involvement—not simply recommend more inspection. ASQ recommends scenario-based interviewing specifically to distinguish real project experience from knowledge of Six Sigma terminology.

6. Ask for a 30/60/90-day plan

A good proposal should tell you:

• What they'll investigate first
• What data they need
• Which employees they'll work with
• Which projects they'll prioritize
• Expected deliverables
• How savings will be measured
• How the plant will sustain the improvements after they leave

7. Structure the contract around outcomes

Rather than paying someone indefinitely to conduct training, consider a defined engagement such as:

Phase 1: Diagnostic + project selection Phase 2: DMAIC projects + implementation Phase 3: Operator/engineer training and coaching Phase 4: Control plan + handoff + benefits verification

Be cautious about consultants whose primary deliverable is a stack of training certificates. You want process improvement that survives after the consultant leaves.

Questions I'd ask every finalist

• “What manufacturing process did you improve that is most similar to ours?”
• “How much measurable scrap, labor, downtime, or capacity did you recover?”
• “Can I speak with that client?”
• “Show me an example of a project that failed. What did you learn?”
• “How do you distinguish correlation from root cause?”
• “How do you validate the measurement system before analyzing process data?”
• “How do you get operators involved?”
• “How do you calculate and verify financial benefits?”
• “What happens when production management disagrees with your recommendation?”
• “What will our team be capable of doing without you after six months?”

Big red flag: someone who spends the interview talking extensively about belts, certifications, and statistical terminology but cannot clearly quantify improvements they personally delivered.

If you tell me your manufacturing industry, plant size, biggest problem (scrap, downtime, yield, throughput, quality, etc.), and approximate consulting budget, I can help you build a consultant selection scorecard and RFP you can send to candidates.

Hiring a Six Sigma consultant to optimize your manufacturing floor requires a structured approach to ensure you find someone with the right expertise, cultural fit, and proven track record in lean manufacturing.

Step-by-Step Hiring Process

1. Define Your Objectives and Scope
   • Identify specific pain points (e.g., high defect rates, long cycle times, excessive waste) and set clear goals for what you want the Six Sigma project to achieve.
2. Determine the Required Certification Level
   • Look for consultants holding a Certified Six Sigma Black Belt (CSSBB) or Master Black Belt (CSSMBB) from recognized bodies like the ASQ Quality Improvement Certification or equivalent reputable organizations.
3. Evaluate Industry-Specific Experience
   • Ensure the consultant has hands-on manufacturing experience relevant to your sector (e.g., automotive, aerospace, discrete or process manufacturing) rather than just transactional or healthcare experience.
4. Review Past Results and Case Studies
   • Ask for concrete examples of previous projects, including quantifiable metrics like ROI, percentage reduction in defects, or throughput improvements achieved for other clients.
5. Establish the Engagement Model
   • Decide whether you need a short-term assessment, a project-based implementation, or a long-term cultural transformation where they train your internal Green and Black Belts.

If you'd like, let me know:

• What specific manufacturing challenge you are trying to solve
• Your company size or approximate production volume

I can help you draft a targeted RFP (Request for Proposal) or interview questions for candidates.

If your goal is measurable improvement in a manufacturing operation, I’d hire a consultant based on demonstrated results rather than simply hiring the person with the most impressive Six Sigma certification.

1. Define the problem before hiring

Give the consultant a specific business mandate, such as:

• Reduce scrap/rework by 25%
• Increase first-pass yield from 91% to 97%
• Reduce machine changeover time by 30%
• Cut cycle time by 15%
• Reduce customer defects or warranty claims
• Improve OEE
• Reduce process variation
• Develop your internal Green Belt/Black Belt capability

A good consultant should be able to translate that into a DMAIC project—Define, Measure, Analyze, Improve, Control—and establish a financial baseline. ASQ specifically emphasizes that a genuine Six Sigma project should quantify both process improvement and business benefit.

2. Decide what type of consultant you actually need

For a manufacturing plant, I'd generally look for a Lean Six Sigma Black Belt or Master Black Belt with substantial plant-floor experience.

• Green Belt: appropriate for smaller, part-time projects.
• Black Belt: better for leading significant cross-functional improvement projects.
• Master Black Belt: appropriate if you're undertaking a broader transformation and want someone to coach multiple projects or build your internal program.

Don't automatically require a particular certification. ASQ, for example, offers recognized Six Sigma credentials, but the certification is only one screening signal.

3. Source candidates

One good starting point is asq.org, which is specifically designed to connect organizations with quality/process-improvement experts.

I'd also look at:

• Independent Lean Six Sigma consultants
• Manufacturing engineering/continuous-improvement firms
• Former plant-level Black Belts
• Consultants with experience in your particular industry
• Referrals from other manufacturers
• ASQ's professional network and local sections

Industry experience matters. A consultant who has reduced scrap in a discrete manufacturing environment may be much more useful to you than someone whose Six Sigma experience is primarily in healthcare or financial services.

4. Make candidates prove they have actually done it

This is probably the most important part.

Don't ask, "Are you a certified Black Belt?"

Ask:

"Walk me through the most difficult manufacturing improvement project you've personally led from Define through Control." Then ask:

• What was the baseline?
• How did you verify the measurement system?
• What was the root cause?
• What data did you analyze?
• What changes did you test?
• How much did the process improve?
• How did you calculate the financial benefit?
• Who initially resisted the change?
• What happened six or twelve months later?
• How did you make the improvement sustainable?

A strong consultant should be able to discuss a project in numbers, not just Six Sigma terminology. ASQ likewise recommends screening candidates on completed projects and documented results rather than the belt credential alone.

5. Ask for references from manufacturing clients

Get 2–3 references from companies where the consultant personally led improvement work.

Ask the references:

1. Did they actually achieve the promised results?
2. Were the savings independently verified?
3. Did the consultant work effectively with operators and supervisors?
4. Did improvements remain after the consultant left?
5. Did they teach your people or simply do the work themselves?
6. Would you hire them again?

That last question is particularly revealing.

6. Structure the engagement around outcomes

Avoid:

"Consultant will provide Six Sigma consulting for six months." Prefer something like:

Phase 1 — Diagnostic: 2–3 weeks Map processes, establish baseline performance, identify high-value opportunities.

Phase 2 — Pilot project: 8–12 weeks Run one carefully selected DMAIC project and demonstrate measurable improvement.

Phase 3 — Deployment: 3–6 months Roll the methodology into additional processes while training internal personnel.

Phase 4 — Sustainment: 30–90 days Verify that gains remain after implementation and transfer ownership to your team.

I'd be cautious about paying primarily for "training days." You want process improvement and capability transfer, not a stack of certificates.

7. Put the right requirements in your RFP

Your RFP should request:

• Manufacturing industries served
• Years of hands-on improvement experience
• Relevant certifications
• 3–5 comparable projects
• Baseline → improvement → financial result for each project
• References
• Proposed methodology
• Project timeline
• Deliverables
• Who will actually perform the work
• Fees and travel expenses
• Expected client resources
• Knowledge-transfer/training plan
• How savings will be validated

For a serious engagement, I'd also ask the consultant to conduct a paid initial diagnostic rather than accepting a six-month proposal based solely on a phone call.

8. Watch for these red flags

Be wary of a consultant who:

• Talks more about certification than results
• Promises a specific savings percentage before seeing your operation
• Can't explain how previous savings were calculated
• Wants to begin by training everyone
• Treats Lean/Six Sigma as a collection of tools rather than a management system
• Doesn't spend meaningful time on the shop floor
• Has little experience with your type of manufacturing
• Can't explain how improvements were sustained
• Proposes dozens of projects before establishing priorities

ASQ describes the Black Belt role as a full-time improvement leader who should be capable of leading projects, mentoring others, and managing the change necessary for improvements to stick.

My recommended hiring approach

If I were hiring for a manufacturing plant, I'd shortlist 3–5 consultants, give each the same description of one real problem, and ask them to conduct a 60–90 minute case discussion.

Then score them on:

Don't select the cheapest consultant. Select the one who can credibly demonstrate that they have solved your kind of problem before.

If you tell me what you manufacture, approximate plant size, and the main problem you're trying to fix (scrap, OEE, yield, downtime, cycle time, quality, etc.), I can also help you determine what type of Six Sigma consultant to hire, what the engagement should cost, and what to put in the RFP.

• Talks more about certification than results
• Promises a specific savings percentage before seeing your operation
• Can't explain how previous savings were calculated
• Wants to begin by training everyone
• Treats Lean/Six Sigma as a collection of tools rather than a management system
• Doesn't spend meaningful time on the shop floor
• Has little experience with your type of manufacturing
• Can't explain how improvements were sustained
• Proposes dozens of projects before establishing priorities

ASQ describes the Black Belt role as a full-time improvement leader who should be capable of leading projects, mentoring others, and managing the change necessary for improvements to stick.

My recommended hiring approach

If I were hiring for a manufacturing plant, I'd shortlist 3–5 consultants, give each the same description of one real problem, and ask them to conduct a 60–90 minute case discussion.

Then score them on:

Hiring a Six Sigma consultant to transform your manufacturing floor requires a strategic approach to ensure you get someone who doesn't just talk theory, but actually moves the needle on your throughput, defects, and bottom line.

Here is a step-by-step roadmap to finding, vetting, and hiring the right expert:

1. Define your scope and goals

• Identify the specific pain points you want to fix (e.g., high scrap rates, long cycle times, bottlenecks in assembly).
• Determine whether you need a mentor/trainer to upskill your internal team (e.g., getting your staff certified as Green or Black Belts) or a hands-on project leader who will drive the improvements directly.

1. Verify credentials and expertise

• Look for a certified Black Belt or Master Black Belt from a reputable organization like ASQ (American Society for Quality) or IASSC (International Association for Six Sigma Certification).
• Ensure they have specific manufacturing experience —someone whose background is purely in transactional or healthcare processes might struggle with the nuances of shop-floor constraints, machine downtime, and supply chain logistics.

1. Source potential candidates

• Leverage professional networks like LinkedIn to search for independent industrial consultants specializing in operational excellence.
• Check specialized boutique consulting firms or independent contractor platforms tailored for manufacturing and engineering expertise.
• Ask for peer recommendations through industry associations or local manufacturing networks.

1. Evaluate past results and case studies

• Ask for tangible evidence of past success, specifically requesting metrics like ROI (Return on Investment), percentage reduction in defects (aiming for near-3.4 defects per million opportunities), or cycle-time improvements they've achieved for similar plants.
• Request client references and actually call them to ask about the consultant's communication style, ability to manage shop-floor resistance, and adherence to timelines.

1. Structure the engagement and contract

• Decide on the payment structure: milestone-based pricing, hourly/daily rates, or a retainer tied to performance metrics.
• Establish clear Key Performance Indicators (KPIs) upfront so success is quantified and mutually agreed upon before signing.

To help narrow down the search, could you tell me:

• What is the primary manufacturing challenge or metric you are looking to fix first?
• Do you prefer an independent consultant or a consulting firm?

If your goal is to improve an actual manufacturing process, I’d hire a consultant based on demonstrated project results—not simply on having a Six Sigma certificate. A good consultant should be able to take a measurable problem through DMAIC (Define, Measure, Analyze, Improve, Control) and leave your team able to sustain the gains. Manufacturing case studies show DMAIC being used for defect reduction and production-efficiency improvements.

1. Define the problem before you search

Write a one-page brief containing:

• Process: e.g., CNC machining, assembly, packaging, injection molding
• Current problem: scrap, defects, downtime, cycle time, yield, OEE, rework, etc.
• Baseline: current defect rate/cost/cycle time
• Target: specific improvement you want
• Time frame: e.g., 3–6 months
• Site/team size
• Industry requirements: automotive, aerospace, medical devices, food, etc.
• Data available: ERP/MES, quality records, SPC data, downtime logs

This makes it much easier to compare consultants on the same assignment.

2. Look for a Black Belt with manufacturing experience

For a substantial plant-level project, I'd generally prioritize an experienced Six Sigma Black Belt or Master Black Belt over someone whose main offering is Six Sigma training.

ASQ maintains a certification registry where you can verify certifications such as Six Sigma Black Belt (CSSBB), and its ASQConnEx service lets organizations search for quality experts.

IASSC also has recognized Black Belt and Green Belt credentials; its Black Belt designation is specifically oriented toward leading complex improvement projects.

3. Require evidence of completed projects

Ask every candidate for 2–3 comparable projects, preferably in your industry.

For each project, ask:

1. What was the baseline?
2. What was the root cause?
3. What data did you collect?
4. Which statistical methods did you use?
5. What changes did you implement?
6. What was the quantified financial/operational improvement?
7. How long did you track the result?
8. Who owned the process afterward?
9. Can you provide a reference who can verify the result?

This is more valuable than simply asking, "Are you certified?" ASQ's current hiring guidance similarly emphasizes completed DMAIC projects, validated results, measurement-system analysis, statistical reasoning, and sustainability after handoff.

4. Test them with your real problem

Give your finalists a simplified version of one of your manufacturing problems.

For example:

"Our machining cell has a 7% scrap rate. The three largest defect categories are dimensional errors, surface finish, and burrs. How would you approach this?"

A strong consultant should discuss things such as:

Define → Measure → Analyze → Improve → Control

and should ask about the measurement system, process variation, data quality, potential causes, experimentation, process controls, and how the improvement will be sustained.

Be cautious if the answer immediately becomes a list of Lean/Six Sigma buzzwords without asking for data.

5. Check industry-specific experience

This matters more than people sometimes realize. A consultant who has improved a semiconductor fab may not automatically be the best choice for a high-volume metal stamping operation.

Match experience to your environment:

• Automotive: IATF 16949, APQP/PPAP
• Aerospace: AS9100
• Medical devices: ISO 13485 and applicable regulatory controls
• Food: food-safety/QMS requirements
• General discrete manufacturing: machining, assembly, welding, molding, etc.

ASQ specifically recommends considering the candidate's sector and standards experience rather than treating Six Sigma expertise as completely industry-neutral.

6. Structure the engagement around outcomes

I'd avoid an open-ended arrangement like "$X per day until the project is finished."

Instead, define deliverables such as:

For a first engagement, a pilot project is often the safest approach. Pick one expensive, measurable problem, prove the consultant can deliver, and then expand the relationship.

7. Compare proposals using a scorecard

I'd weight candidates approximately:

• 30% — Proven manufacturing project results
• 20% — Technical/statistical Six Sigma capability
• 15% — Experience with your manufacturing process
• 15% — References
• 10% — Change-management/leadership ability
• 10% — Price and commercial terms

Don't let a very low day rate outweigh a consultant who can demonstrate, for example, $1M/year of validated savings on comparable manufacturing processes.

8. Red flags

I'd be wary of consultants who:

• Focus heavily on the certificate rather than completed projects
• Promise a specific savings number before seeing your data
• Can't explain how they validated the measurement system
• Treat more inspection as the primary solution to quality problems
• Can't provide references
• Have no experience on a production floor
• Want to train everyone before addressing the business problem
• Can't explain how improvements will remain in place after they leave

A practical hiring process

Week 1: Define the project and desired outcomes.
Week 2: Identify 5–8 candidates through ASQ, industry contacts, referrals, and consulting firms.
Week 3: Interview 3–4 and give them the same manufacturing scenario.
Week 4: Check references and select a consultant for a pilot.
Months 1–3: Run the first DMAIC project with your internal process owner involved.
Afterward: Quantify the results and decide whether to expand.

One particularly important point: make your internal process owner part of the project. The consultant should transfer capability to your organization, not become the person everyone calls whenever the process has a problem.

If you tell me what you manufacture, your approximate company/plant size, and the main problem (scrap, defects, downtime, throughput, cost, etc.), I can also search for specific Six Sigma consulting firms/independent consultants suited to that type of manufacturing and compare them.

Hiring a Six Sigma consultant for manufacturing requires a structured approach to ensure you find someone with the right expertise, cultural fit, and proven track record in lean manufacturing or continuous improvement.

Here is a step-by-step guide to finding and hiring the right consultant:

1. Define Your Objectives and Scope
   • Identify specific pain points (e.g., high scrap rates, long cycle times, bottlenecks in assembly).
   • Decide on the project scope —whether you need a full-scale plant transformation, a targeted DMAIC (Define, Measure, Analyze, Improve, Control) project, or training for your internal staff.
2. Verify Credentials and Experience
   • Look for a certified Six Sigma Master Black Belt (MBB) or Black Belt (BB) from a recognized body (like ASQ or IASSC).
   • Ensure they have specific industry experience in manufacturing rather than just transactional or healthcare environments, as factory floor dynamics require distinct expertise.
3. Source Candidates
   • Use professional networks like LinkedIn or industry-specific organizations.
   • Check consulting directories or platforms like the Association for Manufacturing Excellence (AME) or the Institute of Industrial and Systems Engineers (IISE).
   • Ask for referrals from industry peers or local manufacturing associations.
4. Evaluate Proposals and Interview
   • Request case studies showing quantifiable results (e.g., "$X saved in waste reduction" or "% increase in OEE").
   • Ask how they transfer knowledge to your team so you aren't dependent on them forever.
   • Evaluate their communication style and how well they align with your floor workers and management team.
5. Establish the Contract and KPIs
   • Structure the agreement around milestones and deliverables rather than just an open-ended hourly rate.
   • Define clear Key Performance Indicators (KPIs) such as cycle time reduction, first-pass yield, or cost savings targets.

If you'd like, tell me:

• What is your primary manufacturing challenge or goal?
• Do you need them for hands-on project execution or employee training?

I can help you outline a detailed interview question checklist for your candidates.

A good Six Sigma consultant should be hired as a process-improvement partner, not simply as someone who teaches Six Sigma. For manufacturing, I’d structure the search around a specific business problem and measurable financial outcome.

1. Define the problem before hiring

Write down 1–3 problems such as:

• Scrap/rework is too high
• Yield is below target
• Machine downtime is excessive
• Changeovers take too long
• Customer defects/returns are increasing
• Process variation is causing inconsistent dimensions or performance
• Labor productivity is below target

Give the consultant baseline numbers if you have them—for example, “scrap is 7.2%, costing approximately $450K/year.”

That lets you evaluate consultants based on whether they can actually improve the process. ASQ specifically describes Six Sigma projects as projects that measure process performance and the financial benefit of improvement. testwww.asq.org 

2. Look for a Black Belt or Master Black Belt with manufacturing experience

For a serious manufacturing transformation, I'd generally favor:

Certified Six Sigma Black Belt (CSSBB) — hands-on project leadership, statistical analysis, DMAIC, team leadership.

Master Black Belt (MBB) — useful if you're undertaking a broader company-wide deployment and need someone who can establish the improvement program and coach multiple teams.

ASQ's description of the roles aligns with this distinction: Black Belts lead improvement work using DMAIC, while Master Black Belts operate at the strategic/program level and coach other practitioners.

Certification isn't enough, though. A consultant with a certificate but no experience on a factory floor is usually less valuable than an experienced practitioner who has actually delivered measurable manufacturing improvements.

3. Find candidates through credible sources

One useful starting point is ASQConnEx's expert directory, which allows organizations to search for ASQ-authorized quality experts.

You can also use the ASQ certification registry to verify an individual's ASQ certification. ASQ's CSSBB certification is also independently accredited under ISO 17024, which provides an additional credential check. www.asq.org 

I'd also get referrals from:

• Your equipment suppliers
• Manufacturing-industry associations
• Local ASQ networks
• Other manufacturers in your industry
• Your existing quality/process-engineering contacts

4. Interview them using a real problem

Don't ask merely, “Are you a Six Sigma expert?”

Give each finalist a simplified version of your actual problem and ask:

“How would you approach this in the first 30, 60, and 90 days?”

A strong candidate should naturally discuss things like:

Define → Measure → Analyze → Improve → Control (DMAIC)

and should want to see your actual process, data, operators, equipment, quality records, and financial impact—not just conduct classroom training.

Ask for 2–3 comparable case studies, including:

• Starting problem
• Baseline metric
• Root cause
• Changes implemented
• Improvement achieved
• Dollar savings
• Time required
• Their specific role

The most important question is: “Can I speak with the client who owned that project?”

5. Make the proposal outcome-based

Instead of:

“Consulting: $X per day for six months”

I'd ask for a proposal structured roughly as:

1. Diagnostic phase — map the process and establish baseline
2. Project selection — identify highest-value improvement opportunities
3. DMAIC implementation — execute one or more projects
4. Financial validation — quantify savings with your finance team
5. Control phase — establish metrics, procedures and ownership
6. Knowledge transfer — train your employees so improvements persist

Be cautious about consultants who want to spend months training everyone before demonstrating results.

6. Ask these questions before signing

I'd use these as your interview scorecard:

7. Consider a pilot rather than a large engagement

If you're unsure, hire the consultant for one well-defined project first.

For example:

Reduce Line 3's scrap rate from 6.5% to below 3% within 16 weeks, while maintaining throughput and customer specifications.

That's much easier to evaluate than “implement Six Sigma throughout the company.”

If they deliver, you can expand the engagement.

8. Don't overlook an internal Six Sigma capability

If you have capable process/quality engineers, another model is to hire a consultant for the initial projects and train your internal team. ASQ's Green Belt/Black Belt framework explicitly distinguishes practitioners who support improvement projects from those who lead them.

That can be considerably more sustainable than having an outside consultant permanently own your improvement program.

My preferred approach: hire an experienced manufacturing Black Belt for a paid diagnostic + pilot project, require a quantified baseline and target, verify 2–3 references, and make knowledge transfer part of the contract.

If you tell me what you manufacture, approximate company size, location, and your biggest manufacturing problem (scrap, downtime, yield, cycle time, etc.), I can also help you identify the type of consultant you should hire, what a reasonable engagement structure looks like, and where to find candidates.

Hiring a Six Sigma consultant for manufacturing works best when you treat it like a process-improvement project: define the problem, find someone with relevant plant experience, and tie the engagement to measurable results. A good consultant should focus on outcomes such as lower scrap, fewer defects, shorter cycle times, improved throughput, or reduced variation—not just training or presentations.

1. Define what you want to improve first

Before contacting consultants, document:

• Problem: e.g., high scrap on Line 3, excessive changeover time, customer returns, downtime
• Current baseline: defect rate, OEE, cycle time, yield, labor hours, cost of poor quality
• Target: e.g., reduce defects by 40% in six months
• Scope: one production line, a product family, supplier quality, maintenance processes, etc.

Consultants are much more effective when they can propose a specific DMAIC (Define–Measure–Analyze–Improve–Control) project rather than a vague “improve efficiency” assignment.

2. Decide what type of consultant you need

Common options:

• Six Sigma Green Belt consultant: Good for smaller projects, coaching teams, and focused improvements.
• Six Sigma Black Belt consultant: Better for complex, data-heavy manufacturing problems involving statistics, process capability, experiments, and cross-functional teams.
• Master Black Belt / operational excellence consultant: Useful for plant-wide deployments, training programs, or building an internal continuous improvement system.

For most manufacturers, a Black Belt with direct experience in your industry is often more valuable than someone with certifications alone.

3. Look for manufacturing-specific experience

Ask candidates:

• “What manufacturing environments have you improved?”
• “Have you worked with processes like ours?”
• “What measurable results did you deliver?”
• “Can you show before-and-after metrics?”
• “What role did operators and engineers play in sustaining the changes?”

Strong candidates should be comfortable with tools such as:

• DMAIC
• Statistical process control (SPC)
• Root cause analysis
• Measurement system analysis (MSA/Gage R&R)
• Design of experiments (DOE)
• Process capability analysis
• Value stream mapping
• Lean tools such as 5S and SMED

Certification matters, but demonstrated results and cultural fit are usually more predictive of success.

4. Where to find candidates

Potential sources:

• Professional networks (manufacturing leaders, quality managers, plant directors)
• Industry associations such as the American Society for Quality
• Manufacturing consulting firms
• Independent Lean Six Sigma consultants
• Referrals from other manufacturers

For smaller projects, independent consultants can work well; for multi-site transformations, a consulting firm may provide more resources.

5. Interview them with a real problem

Give finalists a short case:

“Our machining line has a 12% scrap rate. Cycle time varies by 25%, and operators use different methods. How would you approach this?”

A strong consultant should describe:

1. How they would collect data
2. How they would verify the problem
3. How they would identify root causes
4. How they would test improvements
5. How they would ensure the gains remain after they leave

6. Structure the contract around results

A typical engagement might include:

• Assessment phase: 1–3 weeks
• Improvement project: 2–6 months
• Training/coaching: optional
• Sustainment plan: standard work, dashboards, ownership transfer

Avoid contracts that only promise workshops or “Lean training days” without measurable deliverables.

7. Check references

Speak with previous clients and ask:

• Did the consultant achieve the promised results?
• Were improvements sustained after the consultant left?
• Did employees adopt the new processes?
• Would you hire them again?

If you share your industry (automotive, aerospace, food, medical devices, etc.), plant size, and the problem you want to solve, I can suggest what type of Six Sigma consultant profile would fit best and what a reasonable engagement scope might look like.

Hiring a Six Sigma consultant can transform your manufacturing floor, reduce waste, and boost efficiency. Follow this structured roadmap to find, vet, and onboard the right expert for your facility:

1. Define Your Objectives and Scope

• Project goals: Identify what you want to achieve (e.g., reducing cycle time by 20% or lowering defect rates below 3.4 parts per million).
• Scope of work: Determine whether you need a short-term assessment, full project leadership, or internal staff training and mentoring.

1. Verify Credentials and Certifications

• Black Belt or Master Black Belt: Ensure the consultant holds a recognized certification (such as from ASQ or a reputable deployment firm) with a proven track record in a manufacturing environment.
• Industry experience: Look for someone who has specifically worked in your sector (e.g., automotive, medical devices, electronics) and understands your specific regulatory or operational constraints.

1. Source Candidates and Proposals

• Professional networks: Search directories like the ASQ Consultant Directory or leverage LinkedIn to find verified practitioners.
• Request for Proposal (RFP): Send out a clear RFP detailing your manufacturing challenges, expected timeline, and deliverables to get comparable bids.

1. Evaluate Past Results and References

• Case studies: Ask for tangible examples of previous manufacturing transformations they led, including quantifiable metrics and ROI.
• Client references: Speak directly with past manufacturing clients to gauge the consultant’s ability to engage floor-level workers and secure executive buy-in.

1. Establish a Clear Contract and KPI Structure

• Milestone-based payments: Tie compensation to measurable milestones (e.g., phase gate reviews in the DMAIC framework) rather than open-ended hourly billing.
• Knowledge transfer: Ensure the contract includes provisions for training your internal team so improvements are sustainable after the consultant leaves.

If you'd like, let me know:

• What specific manufacturing challenges or waste metrics you are trying to fix
• The size of your facility or team

I can help you draft a customized RFP outline or interview questions to ask candidates.