[Azure AD groups] tips for more efficient rules

Author: curtand

articles/active-directory/enterprise-users/groups-dynamic-rule-streamline.md

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+---
+title: Create simpler and faster rules for dynamic groups - Azure AD | Microsoft Docs
+description: How to optimize your membership rules to automatically populate groups.
+services: active-directory
+documentationcenter: ''
+author: curtand
+manager: karenhoran
+ms.service: active-directory
+ms.subservice: enterprise-users
+ms.workload: identity
+ms.topic: overview
+ms.date: 03/25/2022
+ms.author: curtand
+ms.reviewer: jordandahl
+ms.custom: it-pro
+ms.collection: M365-identity-device-management
+---
+
+
+# Create simpler, more efficient rules for dynamic groups In Azure Active Directory
+
+The team for Azure Active Directory (Azure AD) sees a lot of incidents related to dynamic groups and the processing time for their membership rules. This article contains the methods by which our engineering team helps customers to simplify their membership rule, which then improves processing time.
+
+When writing membership rules to determine what users or devices get added to dynamic groups, there are steps you can take to ensure the rules are as efficient as possible. More efficient rules result in better dynamic group processing times. 
+
+
+## Minimize use of MATCH
+
+Minimize the usage of the 'match' operator in rules as much as possible. Instead, explore if it is possible to use the 'contains,' 'startswith,' or ‘-eq’ operators. Considering using other properties that allow you to write rules to select the users you want to be in the group without using the -match operator. For example, if you want a rule for the group for all users whose city is Lagos, then instead of using rules like:
+
+```powershell
+user.city -match "ago" or user.city -match ".*?ago.*"
+```
+
+It is better to use rules like:
+
+`user.city -contains "ago,"` or
+`user.city -startswith "Lag,"` or
+best of all, `user.city -eq "Lagos"`
+
+## Use fewer OR operators
+
+In your rule, identify similar sub criteria with the same property equaling various values being linked together with a lot of -or operators. Instead, use the -in operator to group them into a single criterion to make the rule easier to evaluate. For example, instead of having a rule like this:
+
+```powershell
+(user.department -eq "Accounts" -and user.city -eq "Lagos") -or 
+(user.department -eq "Accounts" -and user.city -eq "Ibadan") -or 
+(user.department -eq "Accounts" -and user.city -eq "Kaduna") -or 
+(user.department -eq "Accounts" -and user.city -eq "Abuja") -or 
+(user.department -eq "Accounts" -and user.city -eq "Port Harcourt")
+```
+
+It is better to have a rule like this:
+
+```powershell
+user.department -eq "Accounts" -and user.city -in ["Lagos", "Ibadan", "Kaduna", "Abuja", "Port Harcourt"]
+```
+
+Conversely, identify similar sub criteria with the same property not equaling various values, being linked with a lot of -and operators. Then use the -notin operator to group them into a single criterion to make the rule easier to understand and evaluate. For example, instead of using a rule like this:
+
+```powershell
+(user.city -ne "Lagos") -and (user.city -ne "Ibadan") -and (user.city -ne "Kaduna") -and (user.city -ne "Abuja") -and (user.city -ne "Port Harcourt")
+```
+
+It is better to use a rule like this:
+
+```powershell
+user.city -notin ["Lagos", "Ibadan", "Kaduna", "Abuja", "Port Harcourt"]
+```
+
+# Avoid redundant criteria
+
+Ensure that you aren't using redundant criteria in your rule. For example, instead of using a rule like this:
+
+```powershell
+user.city -eq "Lagos" or user.city -startswith "Lag"
+```
+It is better to simply use a rule like this:
+
+```powershell
+user.city -startswith "Lag"
+```
+
+## Next steps
+
+- [Create a dynamic group](groups-dynamic-membership.md)
+