---
sourceDocument: Australia IT Service Management
sourceDocumentLink: https://servicenow-prod.fluidtopics.net/r/it-service-management

 Release :

    - australia

ft:locale :

    - en-US

ft:publication_title :

    - Australia IT Service Management

ft:clusterId :

    - itsm

bundleId :

    - itsm

workflow :

    - Technology


---

# Service Level Agreement (Legacy) engines

# Service Level Agreement (Legacy) engines {#ariaid-title1}

Release version: Australia  
Updated March 12, 2026  
![](https://www.servicenow.com/docs/portal-asset/ico-clock) 1 minute to read  
If you are on an earlier version of the SLA engine, you can upgrade to the 2011 engine
to make use of the complete service level management functionality.  
The SLA engine has three versions: {#c_GetStartedWithSLAs__table_fjl_jhc_cs__entry__2}

| SLA engine version | Description |
|-|-|
| Escalation engine (pre-2010) | Tracks only one SLA per task. |
| The 2010 engine (the Service level management plugin) | Supports multiple SLAs per task. Business rules handle the processing of these SLAs while workflows handle notifications. The majority of logic is in a single large business rule called Process SLAs. |
| The 2011 engine (also part of the Service level management plugin) | The 2010 SLA engine functionality is concentrated into a number of script includes. Provides retroactive pause calculations and enables the customization of SLA condition processing through the use of condition rules. |
[ ]

{#c_GetStartedWithSLAs__table_fjl_jhc_cs}
* **[Legacy SLA fields](https://servicenow-prod.fluidtopics.net/5cNUIDWgDQpRZMHihDA59A)**   
  Previously, only a single SLA could be attached to a task via the Escalation engine. The information for the SLA was stored in the task table using the SLA Due, Made SLA, and Escalation fields.
* **[Upgrade SLA to 2011 engine](https://servicenow-prod.fluidtopics.net/NE0P1lYpJiBK1~5kEJWH3Q)**   
  You can upgrade SLA processing to use the 2011 Engine.
* **[Organize the migration process](https://servicenow-prod.fluidtopics.net/_~M_9eHuzsQgtEGLap58Ag)**   
  There are several ways to convert the old SLAs to the new Task SLAs.
* **[Convert an SLA to an SLA Definition](https://servicenow-prod.fluidtopics.net/yxwlor3QgZwP0iBtYPuUgA)**   
  You must replicate the default SLA record as a new SLA definition.
* **[Reactivate escalation engine](https://servicenow-prod.fluidtopics.net/O8JsFeUkGdBS5cebWUsdRA)**   
  Escalation engine is replaced with 2011 SLA Engine.