lean-waste-analysis

name	lean-waste-analysis
description	Find and remove waste using the 8 wastes (DOWNTIME), value-add analysis, takt/cycle time comparison, bottleneck/constraint identification, and quick-win prioritization. Feeds the DMAIC Improve phase with a ranked elimination roadmap.

Skill: lean-waste-analysis

Invoked by: process-improvement/lean-six-sigma-blackbelt (primary — owns the Improve-phase waste-elimination roadmap). Also used by process-analyst during current-state mapping when the team wants to classify waste before the formal Analyze phase.

When to invoke: after a current-state value-stream map or swimlane exists; when the primary complaint is speed or cost (not variation/defects — that routes to process-capability-and-spc); Kaizen / rapid-improvement events; lean transformation kickoffs.

Output: a classified waste inventory (8 wastes × process steps), a takt / cycle-time comparison identifying the bottleneck, a value-add ratio, and a prioritized quick-win list with effort/impact estimates.

Lean vs. Six Sigma — pick the right tool

Primary symptom	Lean or Six Sigma?
Process is slow — too much wait time, too many hand-offs	Lean — remove waste and flow-blockers
Process is variable / unpredictable — results are inconsistent	Six Sigma — reduce variation (SPC + root-cause analysis)
Process is both slow and inconsistent	Both — lean first for quick wins, Six Sigma to stabilize what remains

This skill addresses the Lean side. Use process-capability-and-spc and root-cause-analysis for the Six Sigma side.

The 8 wastes — DOWNTIME

The DOWNTIME mnemonic covers all eight waste categories:

Letter	Waste	Definition	Office / operational example
D	Defects	Output that fails to meet CTQ; requires rework or causes downstream failure	Invoice with wrong GL code; hire paperwork missing I-9; deployment that fails smoke test
O	Overproduction	Doing more than the next step needs, sooner than it needs it	Generating 50 monthly reports when only 5 are read; sending all applicants to phone screen before résumé review
W	Waiting	Work paused waiting for input, approval, information, or capacity	Support ticket waiting for Tier-2 availability; deployment queued for release window approval
N	Not utilizing talent	Skills, knowledge, or experience not used in the process	Senior engineer manually provisioning environments when automation exists; analyst re-typing data available via API
T	Transportation	Moving work, information, or material unnecessarily	Emailing attachments between systems that could integrate directly; physical documents shipped for signatures
I	Inventory	Work-in-process accumulating in queues between steps	200 unreviewed claims; 40 onboarding packets awaiting manager signature; sprint backlog of 6 months of work
M	Motion	People searching for information, navigating between systems, or physically moving to perform a task	Switching between 4 tools to resolve one ticket; walking to a printer to collect a document to scan back in
E	Excess processing	Doing more work than the customer requires or than the process needs	Generating a 30-page audit report for a 2-page deliverable; running a multi-level approval for a $50 purchase

Step-by-step

Step 1 — Set up the waste walk

A waste walk (Gemba walk) is an observation of the process as it actually runs. Prerequisites:

1. The current-state map exists (from process-mapping skill).
2. The team has access to at least one person who performs each step.
3. The observation is watching and asking, not auditing or criticizing.

The waste walk question for each step: "Is there anything in this step that does not directly move the output closer to meeting the customer's CTQ?"

Step 2 — Classify waste by step

For each step on the current-state map, fill in the waste inventory table:

Process step	Waste type (DOWNTIME)	Description of the waste	Estimated impact
Receive hiring requisition	Waiting, Defects	Requisition often missing salary band; avg 3-day rework loop to get it	3 days added to cycle time in 60% of cases
Route to recruiter	Motion	Recruiter manually checks shared inbox every 2 hours; no automated assignment	Avg 4-hour delay before recruiter sees it
...	...	...	...

Estimated impact can be qualitative (H/M/L) if time data is unavailable, or quantitative (days, %, FTE-hours) if data exists.

Step 3 — Value-add ratio

From the current-state map's VA / BNVA / NVA annotation (see process-mapping skill):

Process efficiency = sum of VA step cycle times / total lead time (end-to-end)

A 5–10% process efficiency is common in office processes — 90–95% of elapsed time is non-value-add. This number is visceral and compelling for sponsors.

If cycle times are not yet measured, flag it: the VSM data-collection step (from process-mapping) is needed before computing efficiency.

Step 4 — Takt time and bottleneck identification

Takt time = available working time ÷ customer demand rate.

Example — deployment pipeline: 8 hours/day available; customer (engineering team) demands 6 production deploys/day.

Takt = 8 hours / 6 deploys = 1.33 hours per deploy

Compare each step's cycle time to takt:

Step	Cycle time	vs. Takt	Status
Code review	45 min	< 1.33h	OK
Integration test	55 min	< 1.33h	OK
Security scan	1.50 h	> 1.33h	Bottleneck
Staging deploy	20 min	< 1.33h	OK

The constraint (bottleneck) is the step whose cycle time exceeds takt — or, when no step exceeds takt, the step with the highest cycle time relative to takt.

Theory of Constraints corollary: improving a non-bottleneck step does not increase throughput. Work on the bottleneck first.

Step 5 — Prioritize waste by effort / impact

Not all waste is equally worth removing. Score each waste item on:

Dimension	Rating
Impact — how much cycle time, cost, or defect rate does removing this waste save?	H / M / L
Effort — how hard is it to remove? (policy change, system change, behavior change)	H / M / L

Priority matrix:

	High impact	Low impact
Low effort	Quick wins — do immediately	Nice-to-have — do if time allows
High effort	Projects — plan and resource	Avoid — not worth it

Quick wins (low effort, high impact) are the first wave of the Improve phase. They build momentum, demonstrate progress to the sponsor, and free up capacity for larger changes.

Step 6 — Build the waste-elimination roadmap

Produce a prioritized list for the Improve phase:

Priority	Waste item	Waste type	Proposed countermeasure	Effort	Estimated impact	Owner
1	Requisition missing salary band → rework loop	Defects	Add salary band as required field in HRIS requisition form	Low	Eliminate 3-day rework in 60% of cases	HRIS admin
2	Manual inbox check every 2 hours	Motion/Waiting	Auto-assign requisitions to recruiter via workflow rule	Low	Reduce avg handoff delay from 4h to < 15 min	Recruiting ops
3	30-page audit report for 2-page need	Excess processing	Redesign report template to 2-page executive summary	Medium	4 FTE-hours per close period	Finance
...	...	...	...	...	...	...

Do not propose a countermeasure without confirming it addresses a proven cause. For high-effort countermeasures, route to root-cause-analysis to confirm the waste source before committing resources.

Lean waste analysis checklist

• All 8 DOWNTIME categories reviewed for every step (not just the obvious ones)
• Waste walk conducted with frontline workers, not from documentation alone
• Process efficiency (VA ratio) calculated or estimated
• Takt time calculated; bottleneck step identified
• Waste inventory table complete with estimated impact
• Quick wins (low effort / high impact) identified and separated from project-level changes
• Countermeasures confirmed against stated waste causes (not guessed)
• Roadmap has named owners for each item
• "Not utilizing talent" category checked — automation / skill-allocation waste is consistently under-identified

Anti-patterns this skill flags

• Skipping the waste walk and filling in the waste table from a meeting room — the actual waste is always different from the perceived waste
• Treating all waste as equal — not prioritizing by effort/impact; the team spends effort on low-impact items
• Working on a non-bottleneck step — improving anything other than the constraint does not increase throughput
• Eliminating BNVA waste (required controls, audit steps) without authority and risk review — some steps that look like waste are legally required
• Proposing "buy a new tool" as a countermeasure without analyzing whether the current tool is misconfigured or misused — technology is rarely the root cause of waste
• Confusing wait time with value-add time — a step where work sits in a queue is Waiting waste, not VA time, even if the queue is in a "work management system"
• Not-utilizing-talent waste consistently missed — the most senior people doing the most automatable work is the highest-leverage waste in most knowledge-work processes

See also

• Skill: ../process-mapping/SKILL.md — provides the current-state map and VA/NVA annotation this skill builds on
• Skill: ../root-cause-analysis/SKILL.md — validate the root of high-effort waste items before committing resources
• Skill: ../control-plan-and-sustain/SKILL.md — sustain quick wins with standard work and poka-yoke
• Template: ../../templates/sipoc.md — the SIPOC that provides the process boundary for the waste walk
• Knowledge: ../../knowledge/dmaic-and-lean-toolkit.md — the full Lean overlay (8 wastes, value-stream mapping, takt analysis)

---

Last reviewed: 2026-06-03 by claude