CLT10 cheat sheet

TPS rests on two pillars: jidoka (stop the process when abnormal conditions occur) and just-in-time (produce what the next process needs, when it needs it, in the amount needed).

The TPS 'house' treats heijunka (production leveling) as the foundation: without leveled volume and mix, JIT and jidoka both degrade into firefighting.

Three sources of waste in operations: muda (non-value-adding activity), mura (unevenness), and muri (overburden of people or equipment); mura and muri usually generate muda.

Lead time (Little's Law): Lead Time = Work in Process / Throughput. Reducing WIP is the fastest lever to shorten lead time at constant throughput.

Takt time = available production time per period / customer demand per period. It sets the pace, not the machine cycle time.

Value is defined only by the customer's willingness to pay; any activity that does not change form, fit, function, or information toward what the customer wants is a candidate for elimination.

The seven classic wastes: overproduction, waiting, transport, overprocessing, inventory, motion, defects; overproduction is the worst because it hides the other six.

Respect for people is a structural element, not a soft add-on: standard work is written by the people doing the work and improved by them, which is why TPS is described as a thinking production system.

A value stream map distinguishes three time categories per process box: value-added time, necessary non-value-added time, and pure waste time; only the first two normally appear as process time.

Rolled throughput yield (RTY) = product of each step's first-pass yield; a line of five steps at 95% each yields 0.95^5 = 77% overall.

Process cycle efficiency = value-added time / total lead time; typical office and service streams run below 5%, and the metric exposes the queue, not the work.

Current-state map conventions: inventory triangles with quantity and days of supply, a timeline ladder under the process boxes, and a separate information-flow layer above.

The timeline ladder is read as inventory days (upper step) plus process time (lower step); the sum is the total lead time used as the baseline for improvement.

A future-state map must answer: takt time, whether to build to a finished-goods supermarket or to shipping, where continuous flow is possible, where supermarkets pull, and what single pacemaker point schedules production.

The pacemaker is the most downstream process that can be scheduled; everything upstream is pulled, and everything downstream flows in FIFO without separate scheduling.

Spaghetti diagram and process activity chart (value-added vs. non-value-added by step) are supporting analyses used to quantify travel and delay before drawing the map.

Kaizen is incremental, participative, low-capital change; kaikaku is radical redesign; both use the same PDCA logic but differ in scope and cycle time.

The 5 Whys is applied to the process, not the person: each 'why' must move one level deeper into the mechanism until it reaches a systemic cause that can be countermeasured.

The three Mu checklist (muda, mura, muri) is applied to a specific operation before selecting countermeasures; eliminating muda alone can increase muri.

Standard WIP and standard inventory are limits, not targets; any excess above the standard is a signal to investigate, not a buffer to consume.

Motion waste is analyzed with the 5S and motion-economy rules; transport waste is analyzed by layout and by the number of material-handling touches per part.

Overprocessing includes tighter tolerances than the customer requires, redundant approvals, duplicate data entry, and extra reports nobody acts on.

Kaizen event structure: define scope and target in one day, measure current state, run the change in the gemba, then standardize and hand off within days, not months.

A countermeasure must be verified against a before/after measure at the same point in the process; without a measure, the change is an opinion.

Continuous flow means one-piece flow at takt; when processes cannot be joined physically, connect them with a supermarket pull system.

Kanban rules: the downstream process withdraws from the upstream; the upstream produces only what was withdrawn; no kanban, no production; kanban always accompanies the part.

Kanban quantity = (average demand per period x replenishment lead time) + safety stock, then divided by container size and rounded to whole containers.

A two-bin or reorder-point system is a pull system with a fixed order quantity; the reorder point equals demand during lead time plus safety stock.

FIFO lanes are used where a supermarket is not justified: they cap inventory by physical capacity and preserve sequence, unlike a pile of stock.

Heijunka box levels both volume and mix by distributing kanban into time slots; it protects upstream from demand spikes and is a precondition for pull.

SMED reduces changeover in two stages: separate internal from external setup, then convert internal to external and streamline both; single-minute means under 10 minutes.

Line balancing assigns elemental work to stations so each station's cycle time is at or just below takt; the theoretical minimum number of stations = total work content / takt time.

Jidoka: give the machine or operator the ability and the duty to stop the line on abnormality; the andon cord is the mechanism, and stopping is expected behavior, not failure.

Successive checks and self-checks place inspection inside the process; poka-yoke (error proofing) prevents the error from being made or passing, rather than detecting the defect later.

Poka-yoke types: contact (shape, pin, fixture), fixed-value (count, weight), and motion-step (sequence enforcement); the best devices require no operator judgment.

A3 problem solving follows: background, current condition, target condition, root-cause analysis, countermeasures, plan, and follow-up, on one page so the thinking is visible.

Root cause analysis distinguishes occurrence (why it happened), detection (why it escaped), and systemic (why the system allowed it); countermeasures are needed for each.

PDCA is the improvement cycle; SDCA (standardize-do-check-act) is the stabilization cycle that must precede the next PDCA turn.

Containment (immediate action) is separated from corrective action: quarantine and sort first to protect the customer, then fix the cause.

Problem-solving quality is judged by whether the countermeasure is verified by data and whether the standard was updated so the problem cannot recur.

Standard work has three elements: takt time, work sequence (the order of manual steps), and standard in-process stock; all three are required for a valid standard.

Standard work is the current best method, is written at the gemba by the team, and is revised whenever the method improves; an unchanged standard for years signals stagnation.

A standard work combination sheet plots manual, machine, and walking time against takt; a standard work chart shows the operator path and material locations.

5S: seiri (sort), seiton (set in order), seiso (shine), seiketsu (standardize), shitsuke (sustain); the first three are physical, the last two are management system.

Visual management rules: the normal condition must be visible at a glance, and any deviation from normal must be obvious without asking anyone.

Andon, kanban, floor markings, shadow boards, and hour-by-hour production boards all work only if a deviation triggers a defined response.

A one-point lesson is a short, single-topic visual instruction attached to a specific standard or defect; it is a teaching tool, not a policy document.

Audit scoring for 5S should be tied to the standard (photo of the correct state), not to opinion, so the score is reproducible by different auditors.

Leader standard work makes the leader's routine (gemba walk, tiered huddle, problem review) explicit and auditable; it is the mechanism that keeps gains from decaying.

Tiered daily management: team huddle at the process, department huddle, and plant review, each with a short agenda, a board, and an escalation rule for unresolved items.

Gemba walk purpose is to observe the process against the standard and ask questions, not to inspect people or to solve the problem for the team.

Respect for people in practice: no blame for surfacing problems, decisions made with the people affected, and leaders who develop problem-solving capability rather than issuing answers.

Change curve management: communicate the reason for change, give a clear picture of the future state, and provide the skills and time to make the transition.

Catchball is the iterative give-and-take between levels during planning; it aligns the plan with reality and builds ownership before execution starts.

A lean culture is measured by behavior: how fast abnormalities surface, whether standards are current, and whether leaders ask why rather than who.

Resistance is often a rational response to unclear expectations or missing capability; the countermeasure is clarity and training, not persuasion.

Hoshin kanri links long-term strategy to annual targets to daily management through nested plans; the X-matrix records objectives, annual targets, improvement priorities, and owners in one view.

A3 structure for a proposal: title, background, current situation, goal, analysis, countermeasures, plan, and follow-up; the constraint is one page, which forces clarity of thought.

A3 is a thinking process, not a form: the author owns the analysis, and the document is revised through dialogue with the coach before and during execution.

Key metrics: safety (recordables), quality (first-pass yield, defects per unit, RTY), delivery (on-time delivery, lead time), cost (productivity, inventory turns), morale (attendance, suggestions implemented).

Inventory turns = cost of goods sold / average inventory value; days of inventory = 365 / turns.

Overall equipment effectiveness = availability x performance x quality; each factor is measured separately so the loss is visible.

Leading indicators (standard work audits, problem closure rate, 5S scores, kaizen participation) predict results; lagging indicators (cost, delivery, defects) confirm them.

Targets are set as a gap between current condition and the desired condition with a deadline; a target without a named owner and a review cadence is a wish.