---
alias: user-guide-how-lot-traveler-is-constructed
description: "The system dynamically builds a Lot Traveler by rendering pages for specified steps"
---

# How A Lot Traveler Is Constructed

In Critical Manufacturing, a Lot Traveler is built dynamically at the time the user requests to print it.

The system constructs the Lot Traveler in two steps:

1. Firstly, a list of **Step** objects for which the Lot Traveler will be printed, is calculated.
2. Then, for each **Step**, the system renders the corresponding Lot Traveler page(s).

This results in a collection of Lot Traveler pages (PrintableDocuments) that is finally printed.

## Calculating the Step list

 The list of **Steps** is calculated using these rules:

* Using the list of **Steps** of the **Material** current **Flow**
* Starts at the current **Step**
* Stops before:
    * The first optional **Step**
    * The first alternate **Sub-Flow**
    * The first step of a different **Area** or **Facility**

## Resolving the Lot Traveler Page(s) for a Step

The **PrintableDocument** that is used as Lot Traveler page of a certain **Step** may be configured in one of these two ways:

* Setting a default **PrintableDocument** for a **Facility** or **Area**, by using the [AreaPrintableDocumentContext](../../../administration/tables/smart-tables/areaprintabledocumentcontext.md) SmartTable.
* Setting the Lot Traveler property of the **Step** object (this takes precedence over the configuration on the previous point)

!!! info
	Steps for which a Lot Traveler page cannot be resolved, will be skipped.