The TRIRIGAWEB.properties file contains the following Gantt properties:

• GANTT_STRICT_MODE
• GANTT_LOCK_STARTED_TASKS
• ALLOW_GANTT_SCHEDULER_UPDATE_ACTUALS
• GANTT_TIMEOUT_MAX

See also 2. Gantt project creation.

If your application administrator has enabled Gantt Strict mode, the project Plan Start date determines the placement of your tasks. With Gantt Strict mode, all first tasks are required to start directly on the project Plan Start date or end directly on the project Plan End date depending on the value that you select for the project Calculate Project From field. First tasks are tasks that do not have incoming dependencies or constraints specified. All next tasks are moved left or right to be as close as possible to their ancestors and to not violate any dependencies or constraints.

By default, the as-shipped IBM® TRIRIGA® applications do not use Gantt Strict mode. When you create tasks, the tasks maintain the start date that you specify. The next tasks are moved left only to correct dependencies, and do not need to be close to their ancestors. Your application administrator can enable Gantt Strict mode by setting GANTT_STRICT_MODE=TRUE in the TRIRIGAWEB.properties file on the IBM TRIRIGA server. This setting is system-wide, so it must be consistent across all servers.

In addition, IBM TRIRIGA provides a "minimal" Gantt Strict mode. When you create tasks, the tasks maintain the start date that you specify. All next tasks are moved left or right to be as close as possible to their ancestors and to not violate any dependencies or constraints. Your application administrator can enable "minimal" mode by setting GANTT_STRICT_MODE=MINIMAL in the TRIRIGAWEB.properties file on the IBM TRIRIGA server. This setting is system-wide, so it must be consistent across all servers.

See also 6. Gantt constraints and dependencies.

By default, the as-shipped IBM TRIRIGA applications, when correcting dependencies and constraints, do not prevent or "lock" the Gantt scheduler from changing the Planned Start or Planned End date of a task that has already started. But your application administrator can enable the "locking" of started tasks, so that only tasks that have not yet started will be corrected, by setting GANTT_LOCK_STARTED_TASKS=TRUE in the TRIRIGAWEB.properties file on the IBM TRIRIGA server. This setting is system-wide, so it must be consistent across all servers.

See also 5. Gantt milestones and planned tasks.

If you set ALLOW_GANTT_SCHEDULER_UPDATE_ACTUALS=FALSE in the TRIRIGAWEB.properties file on the IBM TRIRIGA server, the Gantt scheduler does not update the "actual" field values if the Actual Start date is > 0. If the Actual Start date is not set, the default behavior is followed.

When the property is set to TRUE, the Gantt scheduler updates the Actual Start, End, Working Hours, and Duration values based on the Planned Start date and Actual Percent Complete fields. This business logic is similar to that in the task forms.

The default is TRUE, which reflects the legacy behavior. See the following algorithm:

• If Actual Percent Complete = 100%, set Actual Start, End, Duration, Working Hours to Planned Start, End, Duration, Working Hours.
• If Actual Percent Complete > 0%, set Actual Start, End, Duration, Working Hours to Planned Start, 0, 0, 0.
• If Actual Percent Complete = 0%, set Actual Start to Planned Start if Actual Start > 0, or else set Actual Start to 0, and set Actual End, Duration, Working Hours to 0, 0, 0.