Use > Build > Change Management > Change collision detection > Enable change collision detection

How to enable change collision detection

To enable change collision detection, you must add a business rule to the After change section of the Change process. (For more information, see here.) If you want to also detect change collisions affecting the same device, you must also add a business rule to the Before adding relationship section of the Change process. (For more information, see here.)

The business rule added to the Before adding relationship section of the Change process, checks collisions between change records with matching times when there is a change to their involved device .

For example, assume two change records have matching times but different involved devices. At a later date, if one of the change records is modified so that they have the same involved device, the business rule generates a collision alert. However, where there is the appropriate business rule in the After change section, but not in the Before adding relationship section, change collision is only detected when start or end times are modified.

Change collision detection business rule

This feature uses the Validate no collisions business rule template. There are the following versions:

  • In the After change section of the Change process

    Image of change collision business rule for all changes

  • In the Before adding relationship section of the Change process

    Image of change collision business rule for changes affecting devices

After adding the rule, you should edit it as follows:

Field Value
expression

  • Check for collisions with all changes

    To check for scheduling collisions with all changes, select a matching start and end time. For example, to check for collisions of Scheduled start time and Scheduled end time, type:

    ${current_update.ScheduledStartTime.IsChanged || current_update.ScheduledEndTime.IsChanged}

  • Check for collisions with changes affecting same device

    When you check for collisions with changes that affect the same device (or devices) that the current change affects, you need to add two business rules: one to the After change section of the Change > Processes and Rules tab, and one to the Before adding relationship section. For example, to check for collisions of Scheduled start time and Scheduled end time, and for collisions with changes affecting the same device, type:

    • In the After change section, type:

      ${current_update.ScheduledStartTime.IsChanged || current_update.ScheduledEndTime.IsChanged}

    • In the Before adding relationship section, type:

      ${current_association_update.association_name == 'DeviceAffectedByChange'}

Caution It is possible to create a simple rule using this template without the "If...Then" option and the expression parameter. However, such a rule would run every time a change record is saved (if defined in After change), and on every added association (if defined in Before adding relationship), likely having a materially adverse effect on performance.

It is therefore recommended that you configure this rule template by always including an expression parameter.
start time

Select a suitable start time field. This is the start time of the current change being worked on that change collision detection checks. For example, Scheduled start.

end time Select a suitable start time field. This is the end time of the current change being worked on that change collision detection checks. For example, Scheduled end.
changes

Note: This field displays only for the rule in the After change section of the Change process.

Select:

  • All changes to detect scheduling collisions with all changes.
  • Changes affecting involved devices to detect device collisions.
filters

Select to filter the change records that the business rule is applied to.

You may filter using fields of the following types only

  • BOOLEAN

  • DATE_TIME

  • DOUBLE

  • ENTITY_LINK

  • ENUM

  • INTEGER

  • SMALL_TEXT

For example, you might choose category, or change model, or owner.

start time field

end time field

Select a suitable start time field and end time field.

The business rule compares the start time to end time (as determined above) of the current change record being worked on, with the start time field to the end time field of other active changes.

For example, you might have the following settings:

  • start time - Scheduled start

  • end time - Scheduled end

  • start time field - Scheduled DT start

  • end time field - Scheduled DT end

The business rule then detects change collisions between the Scheduled start and Scheduled end of the current record being worked on, with the Scheduled DT start and Scheduled DT end for all other active changes.

How to add a change collision detection rule to the After change section of the Change process

  1. From the Main menu, select Administration > Configuration > Records.

  2. In the drop-down at the top of the page, select the Change record type.

  3. Select the Processes and Rules tab.

  4. In the left pane, select Change at the top of the tree.

  5. In the main panel, in the After change section:

    1. Click Add.

    2. Click “If…Then” rule.

    3. Select the Validate no collisions rule template, and click OK.

  6. Edit the newly created rule as required, and save your changes. For more information, see Change collision detection business rule.

How to add a change collision detection rule to the Before adding relationship section of the Change process

  1. From the Main menu, select Administration > Configuration > Records.

  2. In the drop-down at the top of the page, select the Change record type.

  3. Select the Processes and Rules tab.

  4. In the left pane, select Change at the top of the tree.

  5. In the main panel, in the Before adding relationship section:

    1. Click Add.

    2. Click “If…Then” rule.

    3. Select the Validate no collisions rule template, and click OK.

  6. Edit the newly created rule as required, and save your changes. For more information, see Change collision detection business rule.