---
title: "Rolled up Lead Time"
slug: "rolled-up-lead-time"
description: "Calculate cumulative lead times for items using BOM structures, optimize planning horizons, and identify bottlenecks with rolled-up lead time insights."
status: "update"
updated: 2026-09-03T09:18:46Z
published: 2026-09-03T09:39:14Z
canonical: "docs.abakion.com/rolled-up-lead-time"
---

> ## Documentation Index
> Fetch the complete documentation index at: https://docs.abakion.com/llms.txt
> Use this file to discover all available pages before exploring further.

# Rolled up Lead Time

## Feature Overview

For a produced item, the lead time isn't just the time it takes to run production on the top-level item — it's the total time needed to have every component and sub-assembly ready first. Rolled Up Lead Time calculates that total: it walks down an item's production BOM (and any nested phantom BOMs beneath it), finds the longest chain of component lead times plus the item's own manufacturing lead time, and stores the result as a single cumulative lead time per item, location, and variant.

The calculation runs in two steps, both started from the same action. First, the manufacturing lead time itself is calculated for every item that uses production order replenishment — by simulating a production order and measuring how long it takes, the same way BC's standard manufacturing lead time calculation works. Second, the rolled-up figure is built on top of that: for each item, the BOM is traversed level by level (down to 50 levels deep, to guard against circular references), and the longest path through components and their own sub-BOMs is combined with the item's own lead time to produce the final rolled-up number.

Once calculated, the rolled-up lead time isn't just a number to look at — it feeds directly into planning. Simple MRP and Direct Replenishment templates can use "Rolled Up Lead Time" as their Calculation Period, meaning the planning horizon for a calculation is driven by how long it actually takes to produce the item, not a fixed date range or a flat lead time figure.

|  |  |
| --- | --- |
| **Pages involved** | Item Card, Reverse Planning – Simple MRP, Reverse Planning – Direct Replenishment, Reverse Planning – Rolled up Lead Time |
| **Entity types supported** | Items with a Production BOM, Assembly BOM, and/or Routing; calculated per item, and per item/location/variant combination where a Stockkeeping Unit exists |
| **Key configuration fields** | Calculate Rolled up Lead Time (report option) |
| **Integrates with** | Simple MRP and Direct Replenishment (Calculation Period = Rolled Up Lead Time on a Planning Template uses this result to size the calculation horizon) |

## Getting Started

1. Make sure the items you want to calculate have a Production BOM, Assembly BOM, and/or Routing set up — items without one are skipped.
2. From the **Item Card**, **Reverse Planning – Simple MRP**, or **Reverse Planning – Direct Replenishment** journal, run the **Calculate Rolled up Lead Time** action.
3. On the request page, leave **Calculate Rolled up Lead Time** checked (the default) to also roll the manufacturing lead times up through the BOM in the same run.
4. Once the calculation finishes, open **Rolled up Lead times** (from the Item Card or from a journal) to review the results per item, location, and variant.
5. If you want planning calculations to use these figures for their horizon, set **Calculation Period** to **Rolled Up Lead Time** on the relevant Planning Template(s).

## Related Features

Rolled Up Lead Time is a supporting calculation for **Simple MRP** and **Direct Replenishment** — a Planning Template in either journal can set its Calculation Period to Rolled Up Lead Time, so the planning horizon reflects the item's actual cumulative production time instead of a fixed period. It has no dependency on Move Demand Dates, Identify Overstock, or Sales Order Handling.

## User Stories

****Calculating rolled-up lead time for a single item from the Item Card****

**As a** production planner **I want to** calculate the rolled-up lead time for one item directly from its Item Card **So that** I can see its true cumulative production time without running a batch calculation

**Setup:**

1. Open the **Item Card** for the item.
2. Run the **Calculate Rolled up Lead Time** action (under the Production action group).
3. Leave the **Calculate Rolled up Lead Time** option checked on the request page and confirm.

> **Note:** This action is only available on the Item Card when the Reverse Planning app is active.

****Calculating rolled-up lead time for a batch of items****

**As a** planning administrator **I want to** run the calculation across a filtered set of items at once **So that** all relevant items have current rolled-up lead times before a planning run

**Setup:**

1. From **Reverse Planning – Simple MRP** or **Reverse Planning – Direct Replenishment**, run **Calculate Rolled up Lead Time**.
2. Set item filters on the request page as needed (item number, location, replenishment system, routing, blocked).
3. Confirm to run the calculation for all matching items.

****Calculating manufacturing lead time only, without rolling it up****

**As a** production planner **I want to** refresh the manufacturing lead time for items without recalculating the full BOM roll-up **So that** I can update base lead times quickly when I don't need the cumulative figure yet

**Setup:**

1. Run **Calculate Rolled up Lead Time**.
2. Uncheck **Calculate Rolled up Lead Time** on the request page before confirming.

> **Note:** Only the manufacturing lead time is recalculated and stored; the rolled-up BOM traversal is skipped.

****Viewing the calculated rolled-up lead time for an item****

**As a** production planner **I want to** see the rolled-up lead time, lot size, and replenishment system for an item at a glance **So that** I can judge whether the item's production time is realistic for my planning horizon

**Setup:**

1. From the Item Card or a Reverse Planning journal, run **Rolled up Lead time**.
2. Review the list, which shows item, location, and variant combinations with their calculated lead time, lot size, and rolled-up lead time.

****Rolling up lead time through nested phantom BOMs****

**As a** production planner **I want to** have the calculation follow phantom (sub-) BOMs automatically **So that** multi-level assemblies get an accurate cumulative lead time without manual tracing

**Setup:**

1. Ensure the item's Production BOM includes lines of type Production BOM (a nested BOM), not only Item lines.
2. Run **Calculate Rolled up Lead Time** as usual.

> **Note:** The traversal follows nested BOMs down to a maximum of 50 levels; a deeper structure raises an error rather than looping indefinitely.

****Getting a location-specific rolled-up lead time****

**As a** production planner **I want to** calculate rolled-up lead time separately for each location an item is stocked at **So that** planning at each location uses the correct local lead time

**Setup:**

1. Ensure the item has a Stockkeeping Unit at the locations in question.
2. Run **Calculate Rolled up Lead Time** with the relevant Location Filter set on the request page.

> **Note:** If a Stockkeeping Unit exists for the item/location, its replenishment system and lead time settings are used in place of the item's own defaults.

****Handling a transfer-replenished item in the roll-up****

**As a** production planner **I want to** have a Transfer-replenished item's lead time reflect the rolled-up lead time of its transfer-from location **So that** transferred items carry forward the true production time from the supplying location

**Setup:**

1. Ensure the Stockkeeping Unit's Replenishment System is set to Transfer, with a Transfer-from Code.
2. Run **Calculate Rolled up Lead Time** for the receiving location — the calculation looks up the rolled-up lead time already calculated at the transfer-from location.

> **Note:** This requires the transfer-from item/location combination to already have a calculated rolled-up lead time on record; otherwise the calculation is flagged as failed.

****Identifying items where the calculation failed****

**As a** planning administrator **I want to** see which items could not be rolled up **So that** I can investigate missing BOM, routing, or SKU data before relying on the figure in planning

**Setup:**

1. Open **Rolled up Lead time**.
2. Check the **Failed to Roll up leadtime** and **Failed to Calculate leadtime** columns for any items marked as failed.

> **Note:** A failure typically means a required BOM, routing, or prerequisite rolled-up record could not be found — it does not stop the batch calculation for other items.

****Using rolled-up lead time as the planning horizon in Simple MRP****

**As a** purchasing planner **I want to** have my Simple MRP template use each item's actual rolled-up lead time as its calculation horizon **So that** the planning period automatically adapts to how long the item really takes to produce, instead of a fixed window

**Setup:**

1. Calculate rolled-up lead time for the relevant items first (see the Getting Started steps above).
2. On the **Reverse Planning – Simple MRP Planning Templates** page, set **Calculation Period** to **Rolled Up Lead Time** on the template.
3. Run Simple MRP using that template.

> **Note:** If an item has no calculated rolled-up lead time, the planning calculation falls back to its standard lead time behaviour for that item.

****Using rolled-up lead time as the planning horizon in Direct Replenishment****

**As a** purchasing planner **I want to** apply the same rolled-up-lead-time-driven horizon to ad hoc Direct Replenishment calculations **So that** manual supply creation is also scoped to a realistic production timeframe

**Setup:**

1. Calculate rolled-up lead time for the relevant items.
2. On the **Reverse Planning – Direct Replenishment Planning Templates** page, set **Calculation Period** to **Rolled Up Lead Time**.
3. Run Direct Replenishment using that template.

## Field Reference

| Field name | Where to find it | What it does | Default value |
| --- | --- | --- | --- |
| Calculate Rolled up Lead Time | Calculate Rolled up Lead Time (request page) | Controls whether the BOM roll-up step runs in addition to the base manufacturing lead time calculation. | Yes |
| Item No. / Location Code / Variant Code | Reverse Planning – Rolled up Lead Time | Identifies the item, location, and variant combination the calculated lead time applies to. | — |
| Replenishment System | Reverse Planning – Rolled up Lead Time | Shows the replenishment system (Purchase, Prod. Order, Transfer) used to determine how the lead time was derived. | — |
| Lead Time | Reverse Planning – Rolled up Lead Time | The item's own manufacturing (or purchase) lead time before rolling up components. | — |
| Lot Size | Reverse Planning – Rolled up Lead Time | The lot size used when the manufacturing lead time was calculated. | — |
| Rolled Up Leadtime | Reverse Planning – Rolled up Lead Time | The cumulative lead time across the item's full BOM/routing structure. | — |
| Failed to Roll up leadtime | Reverse Planning – Rolled up Lead Time | Indicates the BOM roll-up step could not complete for this record. | No |
| Failed to Calculate leadtime | Reverse Planning – Rolled up Lead Time | Indicates the base manufacturing lead time calculation failed for this record. | No |