Skip to content

Strategic Cost Management · Just in Time (JIT)

Kanban and Pull System of Production in JIT

Updated 11 October 2026 · Fact-checked

A pull system makes a part only when the next stage asks for it. Kanban is the card or signal that carries this request. In a push system, production follows a forecast schedule. To solve numericals, find demand during lead time, add safety stock, and divide by container size to get the number of kanbans.

Understand Kanban and Pull System of Production

In a push system, a plan or forecast decides what each stage makes. Each stage produces and pushes output forward, whether the next stage needs it or not. If the forecast is wrong, stock piles up between stages.

In a pull system, the last stage (final assembly) is driven by actual customer demand. It takes parts from the stage before it. That stage then makes only what was taken, to replace it. The signal travels backward from the customer to the first stage. No stage produces without a signal.

Kanban is the Japanese word for card or signboard. It is the tool that carries the signal. A kanban is usually attached to a container holding a fixed quantity of one part. When the user stage opens a container, the card goes back to the supplying stage. That card authorises the supplier to make or move one more container. Without a card, nothing is made.

There are two common types. A withdrawal (move) kanban authorises the movement of a container from the supplying stage to the user stage. A production kanban authorises the supplying stage to make one container of the part. The total number of cards in circulation puts a cap on work-in-progress. Fewer cards means less stock and quicker exposure of problems.

Kanban works best with stable, repetitive production, short set-up times, good quality at source and reliable suppliers. It is a control tool for JIT, not the whole of JIT. If you have wide demand swings or long set-ups, the system needs levelled production and set-up reduction first.

Key rules to remember

Number of kanbans
N = D × L × (1 + S) ÷ C
D = demand per unit time, L = lead time (same time unit as D), S = safety factor as a decimal, C = container capacity in units. Always round N up to a whole number.
Maximum inventory in the loop
Maximum stock = N × C
Cards in circulation multiplied by container size caps the stock for that part.
Lead time
L = waiting time + processing time + move time (+ other delays)
Convert to the same unit as demand before using the kanban formula.
Pull rule
No kanban = no production and no movement
Use this to separate pull from push. Push is driven by schedule or forecast.

How to solve Kanban and Pull System of Production questions

Use this order for a theory or numerical question on kanban and pull systems.

  1. 1Read the question and decide what is asked: explain, compare push and pull, or compute the number of kanbans.
  2. 2For theory, define the pull system first, then the kanban card and its types, then the flow of signals from customer back to supplier.
  3. 3For a comparison, use fixed points: trigger of production, direction of signal, stock level, forecast dependence, and response to change.
  4. 4For a numerical, list D, L, S and C. Convert all to one time unit, for example per hour or per day.
  5. 5Compute demand during lead time as D × L. Apply the safety factor: × (1 + S).
  6. 6Divide by C and round up to the next whole number. State the maximum stock as N × C.
  7. 7If the question asks for a recommendation or effect, link the answer to lower stock, faster problem detection and the need for stable demand.
  8. 8Write one closing line of comment, such as the conditions needed for kanban to work.

Quickest way: Three-line kanban count

When to use it: Use for any numerical that asks for the number of kanbans or containers.

  1. Write D × L first. This gives units needed while one container is being replenished.
  2. Multiply by (1 + S) if safety stock is given. If S is given in units, add it instead.
  3. Divide by C and round up. Check that your time units match before dividing.

Common mistakes in Kanban and Pull System of Production

  • Treating kanban as the same thing as JIT

    Kanban is the most visible JIT tool, so students merge the two.

    Fix: Say that JIT is the philosophy and kanban is one control tool used to run a pull system.

  • Describing the signal as moving forward

    Students picture the product flow and forget the information flow.

    Fix: Material flows forward, but the kanban signal flows backward from the user stage to the supplier stage.

  • Mixing time units in the formula

    Demand is given per day and lead time in hours, or the reverse.

    Fix: Convert D and L to the same unit before multiplying. Write the unit beside each figure.

  • Not rounding the number of kanbans up

    Students round to the nearest whole number or leave decimals.

    Fix: Cards are whole items and rounding down risks a stock-out, so always round up.

  • Saying pull systems need no forecast at all

    The idea of 'no forecast' is overstated from the push versus pull contrast.

    Fix: Say production is triggered by actual demand, but capacity planning and supplier schedules still use some demand estimates.

  • Writing a push versus pull answer without a basis of comparison

    Students write two paragraphs instead of point-wise contrasts.

    Fix: Use clear points such as trigger, stock, lead time, flexibility and fit, and write both systems against each point.

Worked examples

Example 1

Differentiate between push and pull systems of production. Explain how kanban controls a pull system. (6 marks)

Show the solution
  1. Push: production at each stage follows a schedule based on forecast. Output is pushed to the next stage whether needed or not.
  2. Pull: production at a stage starts only when the next stage signals need. Final assembly is driven by actual customer orders.
  3. Stock: push tends to build work-in-progress between stages. Pull keeps stock low because it is capped by the number of cards.
  4. Response: push reacts slowly to a forecast error. Pull adjusts to actual demand but needs stable, levelled production.
  5. Kanban: a card is attached to a container of fixed size. When the user stage uses a container, the card goes back to the supplier.
  6. The production kanban lets the supplier make one more container. The withdrawal kanban lets a container move to the user stage.
  7. No card means no production or movement, so overproduction is prevented and stock is capped at cards × container size.

Answer: Push is forecast-driven and builds stock; pull is demand-driven and kanban cards carry the replenishment signal backward, limiting stock to the number of cards times container size.

Example 2

A component is used at 400 units per day on an 8-hour shift. Lead time to replenish one container is 2 hours. Safety stock is 10% of demand during lead time. Each container holds 25 units. Compute the number of kanbans and the maximum stock of the component.

Show the solution
  1. Demand per hour = 400 ÷ 8 = 50 units.
  2. Demand during lead time = 50 × 2 = 100 units.
  3. Add safety factor of 10%: 100 × 1.10 = 110 units.
  4. Number of kanbans = 110 ÷ 25 = 4.4.
  5. Round up to 5 kanbans.
  6. Maximum stock = 5 × 25 = 125 units.

Answer: 5 kanbans are needed, and the maximum stock is 125 units.

Exam tips

  • Kanban numericals are short. Show D, L, S and C separately so you get method marks even if the final figure slips.
  • Always round the number of kanbans up and say so in one line.
  • In comparison questions, use point-wise contrasts, not a long narrative.
  • In case-based MCQs, check the trigger: if a schedule or forecast starts production, it is push; if a downstream signal does, it is pull.
  • Close a descriptive answer with the conditions needed, such as stable demand, short set-ups and reliable suppliers.

Practice questions from Just in Time (JIT)

Kanban and Pull System of Production in other exams

The same ground in other exams, if you are preparing for more than one or want another angle on it.

Kanban and Pull System of Production: frequently asked questions

What is kanban in JIT in simple words?

Kanban is a card or signal that tells a stage to make or move parts. It is sent back from the stage that used the parts. This way, production happens only when there is a real need.

What is the main difference between push and pull systems?

A push system produces to a forecast schedule and moves output forward. A pull system produces only when the next stage signals need. Pull usually holds less stock but needs stable, levelled demand.

How do you calculate the number of kanbans?

Multiply demand per unit time by lead time, apply the safety factor, and divide by container size. Use the same time unit for demand and lead time. Round the result up to a whole number.

Are there different types of kanban cards?

Yes. A withdrawal kanban authorises moving a container from supplier stage to user stage. A production kanban authorises the supplier stage to make one more container. Some questions mention only these two.