Lean Bronze cheat sheet

Lean definition: delivering value from the customer's perspective while eliminating waste (muda) and continuously improving flow; the two pillars are continuous improvement and respect for people.

Seven classic wastes (TIMWOOD): Transportation, Inventory, Motion, Waiting, Overproduction, Overprocessing, Defects; an eighth, unused human talent, is often added.

Three Ms: muda (waste), mura (unevenness), muri (overburden); removing muda without addressing mura and muri usually shifts problems elsewhere.

Value is defined by the customer and by three conditions: the customer cares about it, it changes the product or service, and it is done right the first time.

Five Lean principles: specify value, map the value stream, create flow, establish pull, pursue perfection.

Gemba means the actual place where work happens; decisions and observation belong there, not in a conference room.

Respect for people means engaging the people who do the work in designing it, not simply being polite; standard work is the baseline for improvement, not a constraint on it.

Kaizen is small, frequent, low-cost improvement by the people doing the work; kaikaku is radical, large-scale transformation.

Culture enablers: leader standard work, daily management, visual management, and a blame-free problem-escalation norm; without them tools decay after the event ends.

PDCA / PDSA cycle: Plan (define problem, target, root cause), Do (pilot), Check/Study (compare result to target), Act (standardize or adjust); repeat.

DMAIC ordering: Define, Measure, Analyze, Improve, Control; used for problems with unknown cause and measurable data.

Five Whys drives to root cause by asking why iteratively; stop when the answer is a systemic cause the team can act on, not a person.

Fishbone (Ishikawa) categories commonly used: Man, Machine, Material, Method, Measurement, Mother Nature (environment).

Pareto principle: roughly 80% of effects come from about 20% of causes; a Pareto chart ranks causes by frequency or cost to focus effort.

A3 thinking: one-page story on a single sheet covering background, current state, target, root cause analysis, countermeasures, plan, and follow-up.

Countermeasure vs. solution: a countermeasure is a targeted, reversible action against a root cause; it is tested and adjusted rather than declared final.

Standard work three elements: takt time, work sequence, and standard in-process inventory; without a standard there is no basis for judging improvement.

Poka-yoke is error-proofing that prevents a defect from being made or passed on; it is a countermeasure at the source, not inspection at the end.

Leader standard work: leaders follow a documented daily/weekly routine (gemba walks, tiered meetings, audits) so improvement is managed, not hoped for.

Tiered daily management: short team huddles escalate issues up through levels with a defined response time at each tier.

Visual management rule: any deviation from standard is visible within one shift, at the point of work, without asking anyone.

Accountability vs. blame: problems surface and are owned by the process owner; punishing the messenger suppresses reporting and hides defects.

Hoshin kanri (policy deployment): a small set of breakthrough objectives cascades to annual targets and daily actions, with catchball dialogue up and down.

Catchball is the two-way negotiation of targets and resources between levels; it builds ownership and surfaces capacity constraints before commitment.

Change curve awareness: expect resistance, denial, and testing before adoption; involvement in design shortens it more than communication alone.

Training within Industry (TWI) job instruction: prepare, present, try out, follow up; standard work is only sustained when people are taught it the same way.

Sustainment test: the improvement survives staff turnover and leadership change only if it is built into standard work, visual controls, and leader routines.

Value stream mapping symbols: process box, inventory triangle with count, push arrow, FIFO lane, supermarket, kanban withdrawal, truck shipment, kaizen burst.

Value stream map metrics: takt time = available work time / customer demand; lead time = total inventory / daily demand (Little's Law).

Process cycle efficiency = value-added time / total lead time; typical office and service streams sit in the low single-digit percent.

Current-state map is drawn at the gemba with actual counts and times; the future-state map sets a target condition, then an implementation plan with owners and dates.

Push vs. pull: push schedules work against a forecast; pull authorizes production by downstream consumption, typically with kanban.

Kanban rules: downstream withdraws, upstream produces only what is withdrawn, no kanban means no production, and kanban quantity is limited.

Heijunka is leveling of volume and mix over time; it reduces mura and makes pull and standard work feasible.

SMED (single-minute exchange of die) steps: separate internal from external setup, convert internal to external, streamline remaining elements; target single-digit-minute changeovers.

Little's Law: WIP = throughput x lead time; cutting WIP at fixed throughput shortens lead time proportionally.