CLC cheat sheet

Value = what the customer will pay for; every step that does not change form, fit, or function of the product for the customer is non-value-added (waste).

The three value-stream activities: value-added, necessary non-value-added (Type 1 muda), and pure waste (Type 2 muda); only Type 1 is tolerated short term.

The eight wastes (TIMWOODS): Transport, Inventory, Motion, Waiting, Overproduction, Overprocessing, Defects, Skills underutilized.

Takt time = available production time / customer demand; it sets the pace, not the cycle time of any single machine.

Cycle time = time between one unit leaving a process and the next unit leaving; compare to takt to find the constraint.

Lead time = total time a unit spends in the value stream, including queue and wait; Little's Law: Lead time = WIP / Throughput.

Flow efficiency = value-added time / total lead time; a typical batch value stream runs below 5%.

Process cycle efficiency and percent value-added are computed from the same ratio and are often used interchangeably in lean audits.

A current-state map records customer demand, supplier, process boxes with cycle time, changeover time, uptime, and inventory triangles between boxes.

A future-state map is drawn to takt time, using continuous flow where possible, pull (supermarket/FIFO) where flow is impossible, and a pacemaker process.

Inventory days = inventory quantity / daily customer requirement; convert each triangle to days to compare queues on one scale.

Total lead time on a map = sum of inventory days plus sum of process cycle times; total value-added time = sum of value-added process times only.

The pacemaker is the most downstream continuous-flow process; it is scheduled and all upstream processes are pulled from it.

Kaizen bursts on a map mark improvement opportunities; each should have an owner, target condition, and due date.

A spaghetti diagram traces physical operator or material travel and exposes transport and motion waste a process box hides.

Map the door-to-door scope first; mapping a single department hides the interdepartmental waiting that dominates lead time.

Continuous flow means one-piece flow at takt; it is chosen when processes can be co-located and cycle times are balanced to takt.

Pull means a downstream process signals consumption upstream; the signal is a kanban card, empty container, or electronic trigger.

Kanban quantity = (average demand x replenishment lead time) + safety stock, divided by container quantity, rounded up.

A two-bin (kanban) system reorders when the first bin empties; reorder point = demand during lead time + safety stock.

A supermarket decouples a fast, unreliable upstream process from a downstream pacemaker; a FIFO lane decouples two processes with matched but unequal cycles.

WIP cap is the maximum cards in the loop; lowering the cap exposes problems but must not starve the pacemaker.

Heijunka (leveling) sequences product mix and volume over a fixed pitch; pitch = pack-out quantity x takt time.

A pacemaker interval (pitch) sets the frequency of withdrawal, not the frequency of production at every upstream process.

PDCA: Plan (target condition and current condition), Do (trial), Check (measure against target), Act (standardize or re-plan).

A3 problem solving: background, current condition, target condition, root cause analysis, countermeasures, plan, follow-up on one page.

5 Whys drives to a root cause; a good chain ends at a systemic cause the team can act on, not at 'operator error'.

Fishbone (Ishikawa) 6M categories: Man, Machine, Material, Method, Measurement, Mother Nature (environment).

Standard work has three elements: takt time, work sequence, and standard in-process stock; it is the baseline for all kaizen.

SMED separates internal from external setup; target is single-minute (under 10 minutes) exchange of dies.

TPM pillars include autonomous maintenance, planned maintenance, and focused improvement; OEE = Availability x Performance x Quality.

Kaizen is small, incremental, low-cost, and operator-led; kaikaku is radical redesign; both use the same PDCA discipline.

OEE = Availability x Performance x Quality; world-class benchmark is often cited as 85%, with 90% availability, 95% performance, 99% quality.

Availability = run time / planned production time; Performance = (ideal cycle time x count) / run time; Quality = good count / total count.

First pass yield (FPY) = units passing first time / units entering; rolled throughput yield (RTY) = product of each step's FPY.

Dock-to-dock lead time and on-time delivery are customer-facing metrics; OEE and downtime are internal process metrics.

Lean leaders use gemba walks, ask open questions, and develop people through daily kaizen rather than command-and-control.

Resistance to change is addressed by involving operators in designing the new standard and by making the problem visible.

A value-stream manager owns the whole stream's flow and lead time, crossing functional department boundaries.

Visual management makes the standard and abnormal condition visible at a glance; an andon signals abnormality for immediate response.

Respect for people and continuous improvement are the two pillars of the Toyota Production System; neither works without the other.

Leaders go to the gemba (actual place) to see the actual process and the actual part, rather than reviewing reports.

Hoshin kanri cascades breakthrough objectives into annual plans and daily management; catchball is the two-way negotiation of targets.

Daily management uses tiered accountability: team huddle, value-stream review, and plant review at defined intervals.

Lean transformation sequence: purpose and value, value stream map, flow, pull, perfection; skipping flow and jumping to pull fails.

A pilot value stream proves the model before expansion; scaling requires standard work, training within industry, and leader standard work.

Sustainment requires audit of the process (layered process audits) and of leader behaviors (leader standard work), not just results.

The biggest failure mode is treating lean as a toolbox of events; tools without a management system revert within months.