When one asset on a production line stops, it usually stops the rest of the line with it. A jam on one machine leaves the others with nothing to run, so they go down too. It is really one event, but it used to mean entering the same cause separately on every asset that stopped. Cause Sharing lets the assets on a line share a single cause: you enter the reason once on the asset that stopped, and LEAN applies it to the connected assets up and down the line for you.
Cause Sharing
For operators justifying downtime on LEAN.
You justify a downtime exactly as you do today. Once your line is set up for Cause Sharing, LEAN takes the cause you enter on one asset and automatically assigns the same cause to the connected assets whose downtime started around the same time. There is no separate "share" button to press, and no need to re-enter the event on each machine.
What you do
When a downtime needs a cause, justify it the way you normally would: from the cause-entry alert, the asset dashboard, or the asset timeline, select the cause and resolve the event.
LEAN checks the connected assets on the line and applies the same cause to any whose downtime started within the connection's Product Transit Time, whether they stopped just before or just after. This happens on its own, with no extra step from you.
On those assets, the shared cause appears on the timeline as the justification for the event. In the Data Entry Report it is labelled "Cause sharing", so it is clear where the cause came from.
Input as usual:
Phase details on a phase with a shared cause:
How far a cause spreads
Along the line, one asset at a time. The cause moves upstream and downstream from the asset you justified, hop by hop, and keeps going until it reaches an asset that already has a cause, an asset whose stop falls outside the connection's Product Transit Time, or a shared asset.
Timing is based on when each asset stopped, not when you entered the cause. An asset that goes down a little later still receives the cause as long as its downtime started within the Product Transit Time. An upstream asset whose downtime has already ended can receive it too.
One share per cause you enter. Each manual cause is shared to a given asset at most once. If an asset has more short stops afterward, those are left for someone to justify, so the system never assumes a cause for later stops. It is always better to miss a cause than to record the wrong one.
Shared assets
An asset that feeds more than one line, such as a palletizer shared by several lines, is a shared asset. A shared asset does not receive shared causes, so propagation stops when it reaches one.
You stay in control
You can change an automatically shared cause at any time by editing that asset's timeline and choosing a different cause. Your manual edit is the final word and will not be overwritten. You can also choose to propagate the cause when you are editing an event along the cause propagation chain.
How to set up Cause Sharing
For admins wanting to add Cause Sharing to their production lines
The Product Transit Time is the one setting that controls Cause Sharing on each connection between two assets. It is a single time value, in seconds, that defines the largest gap allowed between the downtime start times of the two assets for their stops to be treated as the same event. It reflects the physical buffer between them: How long the downstream asset can keep running before it starves after the upstream asset stops, or how long before the upstream asset jams after the downstream asset stops.
Key rule. One Product Transit Time value applies to both directions of a connection. It must be a whole, positive number of seconds. If it is left blank, Cause Sharing will not run on that connection.
Quick configuration guide
Setting up Cause Sharing on a line takes three steps:
Create a facility layout. Map each production line so it is clear which assets are connected and in what order, and note what sits between each pair, a conveyor, an accumulator, or a grouping or packaging step, along with any assets that are shared across lines. This is the picture support needs to switch Cause Sharing on, and the basis for every Product Transit Time you set.
Work out the Product Transit Time for each connection. For every pair of connected assets, set the Product Transit Time, the largest gap allowed between their downtime start times. Follow How to choose the value below.
Reach out to support. Send your facility layout and Product Transit Times to LEAN support at [email protected]. The team switches Cause Sharing on for your connections and helps you get started.
Suggested facility layout format. For each line, capture one row per asset, in production order from the first asset to the last:
Line | Asset Name | Downstream asset | Transit Time | Shared asset? |
Line 3 | Filler | Capper | 60 seconds | No |
Line 3 | Capper | Labeller | 60 seconds | No |
Line 3 | Labeller | Case packer | 60 seconds | No |
How to configure the line in the Admin Portal
If you have Admin Portal access you can configure the line yourself; otherwise, LEAN support sets it up for you. Here is how a production line is configured:
Open the production line. In the Admin Portal, go to Production lines. Each line is listed with its facility and asset count. Filter by facility or use the search box to find the line, or select Add production line to create a new one.
Name the line. Give it a name that is unique within the facility.
Enable cause propagation. Tick Enable cause propagation from unplanned downtime to share causes from unplanned stops. Also tick Enable cause propagation from planned downtime if planned events, such as changeovers and shutdowns, should share causes too. At least one must be on for Cause Sharing to run.
Assign the assets. In Available assets, select the assets on this line and move them to Chosen assets with the arrow button. Only unassigned assets from the same facility appear; use the back arrow to remove one.
Check the Chain Visualization. It shows the order LEAN has inferred, for example Process 2 → Process 4 → Process 6. Confirm the assets run in the right sequence.
Add the asset connections. Under Asset connections, add one row per connection: choose the Upstream asset and the Downstream asset, then enter the Product Transit Time (seconds) for that pair. Use How to choose the value below to work out the number. Select Add another Asset connection for each further link, and tick Delete? to remove one.
Save. Use Save, Save and add another, or Save and continue editing.
How to choose the Transit Time value
Work through the buffer between the two assets and add up the time it represents:
Identify the buffer. Walk the line between the two assets and note what separates them: a conveyor, an accumulator, a packaging or grouping step, or simply empty belt space.
Measure the slowest travel time. Time a product from the upstream sensor to the downstream sensor at the slowest speed the line runs at. Some SKUs and warm-up runs are slower, so use the worst case, not the average. This is your baseline.
Add a grouping margin. If the downstream asset packs products in batches, for example, 12 units per case, the last unit moves faster than the first, as the first unit on the case has to wait for an additional 11 units to complete the case. Add a margin for that variance.
Add accumulator buffer. If an accumulator sits between the assets, estimate how many seconds of product it holds at the slowest throughput and add that.
Adjust for the Downtime Delay difference. Subtract the upstream asset's Downtime Delay from the downstream asset's. If they are equal, this is 0. If the downstream delay is longer, add the difference; if it is shorter, subtract it.
Set the Product Transit Time. Add the parts together and enter the total as the Product Transit Time for that connection.
Suggested formula.
Product Transit Time = Slowest Travel Time + Grouping Margin + Accumulator Buffer + (Downstream Downtime Delay minus Upstream Downtime Delay)
What affects the value
Factor | How it affects the Product Transit Time |
Conveyor length and speed | Use the slowest line speed, not the average. A slower SKU or warm-up run lengthens the travel time between sensors. Using the worst case prevents missed shares on slow runs. |
Accumulator capacity | Accumulators decouple the two assets. The more products they hold, the higher the Product Transit Time needs to be. |
Batch or packaging grouping | When the downstream asset groups products (for example, 4 bags per box, 12 boxes per case), add seconds to cover the wait for a batch to complete. |
Downtime Delay difference | What matters is the difference between the two assets' Downtime Delays, not the individual values. Equal delays mean this term is 0. A longer downstream delay widens the Product Transit Time; a shorter one tightens it. |
Line topology | On a single line the Product Transit Time is straightforward. On a one-to-many or many-to-one line, work out each connection on its own. |
Shared assets | Shared assets do not receive shared causes, so no Product Transit Time is needed on the receiving side of a shared asset. |
Tip. It is better to miss a cause than to share the wrong one. Start conservative with a lower Product Transit Time and raise it gradually. After go-live, review the Propagation Log in the Admin Portal: it shows the actual gap in seconds between each pair of stops, which you can use to calibrate and refine each Product Transit Time.
Reach out to LEAN support at [email protected] with your line layout and Product Transit Times. Our team can help you get started.