Work tracking, process, and project limits - Azure DevOps Services (2024)

A work item revision limit of 10,000 is in effect for updates made through the REST API for Azure DevOps Services. This limit restricts updates from the REST API, however, updates from the web portal are not affected.

The default maximum attachment size is 4 MB. You can change the maximum size up to 2 GB.

When working with teams, work item tags, backlogs, and boards, the following operational display and object limits apply.

Each backlog can display up to 10,000 work items. This is a limit on what the backlog can display, not a limit on the number of work items you can define. If your backlog exceeds this limit, then you may want to consider adding a team and moving some of the work items to the other team's backlog.

Additional notes:

• Completed or closed work items don't display on the backlogs and boards once their Changed Date is greater than a year old. You can still list these items using a query. If you want them to show up on a backlog or board, then you can make a minor change to them which resets the clock for display.
• Avoid nesting backlog items of the same type. To learn more, see Fix reordering and nesting issues.
• Avoid assigning the same area paths to more than one team. To learn more, see Limitations of multi-team board views.
• By default, work item limits might be initially configured to lower values.

When working with teams, work item tags, backlogs, and boards, the following operational limits apply. Default and maximum limits.

Each backlog can display up to 999 work items. If your backlog exceeds this limit, then you may want to consider adding a team and moving some of the work items to the other team's backlog.

Additional notes:

• Avoid nesting backlog items of the same type. To learn more, see Fix reordering and nesting issues.
• Avoid assigning the same area paths to more than one team. To learn more, see Limitations of multi-team board views.

For the On-premises XML process model, you can modify the backlog and taskboard limits by editing the ProcessConfiguration.xml file. For details, see Process configuration XML element reference.

Note

Above 300 projects certain experiences, such as connecting to a project from Visual Studio, may start to degrade.For on-premises Azure DevOps Server, there are no hard limits to the number of projects. However, you may find performance issues if the number of projects approaches 300. If you plan to migrate your on-premises collection to Azure DevOps Services, you'll need to observe the maximum limit of 1000 projects. If your collection has more than 1000 projects, you'll either need to split the collection or delete older projects.

The following table lists the maximum number of objects that you can define for the Inheritance and Hosted XML process models. While these represent hard limits, practical limits may also apply.

For additional restrictions and conformance requirements of the Hosted XML process model, see Customize a process when using Hosted XML.

The following table lists the maximum number of objects that you can define for the Inheritance and On-premises XML process models. While these represent hard limits, practical limits may also apply.

• Minimize the number of custom fields you define. All custom fields contribute to the total allowed for a process, collection, or organization. Note that you can specify different behavior for the same field in a different WIT. That is, you can specify different rules, picklists, and more.
• Minimize the number of rules you define for a WIT. While you can create multiple rules for a WIT, addition rules can negatively impact performance when a user adds and modifies work items. When users save work items, the system validates all rules associated with the fields for its work item type. Under certain conditions, the rule validation expression is too complex for SQL to evaluate.
• Minimize the number of custom WITs you define.

• Minimize the number of custom fields you define. All custom fields contribute to the total allowed for a process, collection, or organization. Note that you can specify different behavior for the same field in a different WIT. That is, you can specify different rules, picklists, and more.
• Minimize the number of rules you define for a WIT. While you can create multiple rules for a WIT, addition rules can negatively impact performance when a user adds and modifies work items. When users save work items, the system validates all rules associated with the fields for its work item type. Under certain conditions, the rule validation expression is too complex for SQL to evaluate.
• Minimize the number of custom WITs you define.
• Minimize the number of reportable fields you define. Reportable fields impact performance of your data warehouse.

Note

Work Item Rules Validation Exceeds SQL Limits: A single SQL expression is defined per project to validate work items whenever they are created or updated. This expression grows with the number of rules you specify for all work item types defined for the project. Each behavioral qualifier specified for a field results in an increase in the number of sub-expressions. Nested rules, rules that apply only on a transition or conditioned on the value of some other field, cause more conditions to be added to an IF statement. Once the expression reaches a certain size or complexity, SQL can't evaluate it any more and generates an error. Removing some WITs or eliminating some rules, can resolve the error.

Rate limits

To reduce costs and to enhance scalability and performance, Azure DevOps Services, like many Software-as-a-Service solutions, uses multi-tenancy. To ensure good performance and reduce the likelihood of outages, Azure DevOps Services limits the resources individuals can consume and the number of requests they can make to certain commands. When these limits are exceeded, subsequent requests may be either delayed or blocked.

Most rate limits are reached through REST API calls or non-optimized queries. To learn more, see the following articles:

• Rate limits
• Best practices (to avoid hitting rate limits)

• About process customization and inherited processes
• Create an Inheritance process
• Best practices
• Naming restrictions and conventions

• Customize your work tracking experience
• About process customization and inherited processes
• On-premises XML process customization
• Rules and rule evaluation
• Naming restrictions and conventions