Heijunka mix and pitch release

Heijunka mix and pitch release

Level both volume and mix over a useful planning horizon. The exercise has 400 available minutes and demand for 300 units, giving an 80-second takt. Six units make an eight-minute pitch. Fifty packs therefore fill the horizon. Repeating AABAB ten times releases 30 A packs and 20 B packs: 180 A units and 120 B units. The box makes the next release and any missed interval visible. Before trialing this pattern, verify changeover time, capacity and actual demand. A tidy repeating schedule is not permission to produce items that are no longer needed.

Follow the method

1. Daily mix
2. Pitch
3. A A B A B
4. Repeat ten times

Reconcile five pitches with the whole day

Fictional A/B line: 400 net minutes must serve demand for 180 A and 120 B. Each authorized pack holds six units. Planner Celia proposes the repeating pattern A, A, B, A, B and asks the team to check its quantities, timing and operating assumptions.

Follow the method

1. Slots 1–5
2. Ten patterns
3. Daily A
4. Daily B
5. Capability

A release box is a plan, not proof of capability

Build and reconcile a leveled mix pattern from demand and pack size, while distinguishing a mathematically balanced release plan from a feasible production method.

Fictional A/B line: 400 net minutes must serve demand for 180 A and 120 B. Each authorized pack holds six units. Planner Celia proposes the repeating pattern A, A, B, A, B and asks the team to check its quantities, timing and operating assumptions.

Role: Production planner with operators, quality and changeover owner.

Normal condition

The release pattern represents wanted mix within the available period, with feasible capacity and quality controls.

The gap

A neat sequence can conceal infeasible changeovers or obsolete demand.

• Takt is 80 seconds per required unit.
• No measured changeover or cycle capability is supplied; the release plan remains a teaching proposal.

1. Establish takt and pitch

   Celia divides 400 × 60 by 300 to obtain 80 seconds per unit. She multiplies by six units per pack and converts 480 seconds to eight minutes per release interval.

   Why: Takt is per unit; pitch groups that rhythm into a practical pack-level interval. Confusing the units would make the board impossible to reconcile.

   Evidence: 80 sec/unit × 6 units = 480 sec = 8 min per pitch.

2. Read one complete pattern

   Mark five consecutive eight-minute slots A, A, B, A, B. Three A packs give 18 A; two B packs give 12 B. The pattern spans 40 minutes.

   Why: One complete repeat exposes both mix and volume. Counting colored slots without pack quantities could confuse packs with finished units.

   Evidence: One pattern: 30 units, comprising 18 A and 12 B.

3. Reconcile the whole planning period

   Repeat the pattern ten times. The plan contains 50 pitches, 30 A packs and 20 B packs. Compare both product totals with demand.

   Why: A total of 300 is insufficient if it contains the wrong product mix. Time and each product quantity must agree independently.

   Evidence: 50 × 8 = 400 min; A = 30 × 6 = 180; B = 20 × 6 = 120.

4. Check whether the release can be performed

   The team checks changeovers, equipment response, staffing, material readiness and first-piece acceptance against the proposed sequence. It records missing capability data instead of assuming eight minutes is available for any amount of work.

   Why: Leveling depends on operating conditions. A visually level board does not absorb unmeasured setup losses or make unavailable material eligible.

   Evidence: Feasibility review names the changeover owner and required timing/quality evidence.

5. Respond to actual demand and abnormality

   Record plan versus eligible completion by pitch and make exceptions visible. Review the pattern when demand or pack size changes; preserve the approved quality response when a pack cannot be completed.

   Why: Heijunka is not permission to make an obsolete mix simply to fill every box. The pattern serves customer demand.

   Evidence: A missed pitch has a cause and response; it is not silently filled with another unwanted product.

The requested mix changes

Confirmed demand becomes 150 A and 150 B, still totaling 300.

Rebuild the mix pattern; retaining the old pattern would make 30 excess A and leave 30 B short.

The unchanged total and takt do not make the old product sequence correct.

New plan reconciles each product separately before release.

Run a practice session

Materials

• Two colors of blank pack tokens and a pitch grid
• Calculator; separate changed-demand card

1. Translate demand to packs · 4 minutes

   Which units belong on the release interval?

2. Fill one five-slot pattern · 7 minutes

   Where do 18 A and 12 B come from?

3. Solve the A/B/B variant · 9 minutes

   Can both mix and time be reconciled?

4. Challenge feasibility · 5 minutes

   What could make a correct calculation impossible to run?

Debrief

• Ask what changes when mix changes but total demand does not.
• Distinguish leveling from suppressing a quality signal.

Build one repeat first, then multiply and audit the total against each input.

Transfer into the work

Owner: Planning owner with line and changeover representatives

Record: Mix/pitch plan, feasibility evidence and pitch exceptions

Review: At each planning-basis change and during the controlled trial

Evidence: Wanted units completed with valid quality status and feasible changeover conditions

Revise the release pattern or enabling conditions; do not use overproduction to make the board look complete.