Microsoft Project Desktop Scheduler › How Manual Calculation Impacts the Schedule in Microsoft Project

How Manual Calculation Impacts the Schedule in Microsoft Project

The Calculation option in Microsoft Project is set to On by default. As a result, when you open a CA Clarity PPM project in Microsoft Project, the project is recalculated. The start and finish dates of tasks are automatically adjusted to respect the dependency chain between them. For example, create two tasks, Task 1 and Task 2, with a Finish/Start dependency between them. The start date of Task 2 is calculated relative to the finish date of Task 1 based on the dependency link. The Gantt chart is also updated accordingly. The subsequent tasks are calculated similarly summing up the task level values for Remaining Work, Actual Work, and Work at the Summary Task level.

Prerequisites:

• Verify that you have compatible versions of CA Clarity PPM and Microsoft Project. For more information, see the Compatibilities section of the Release Notes.
• Before you upgrade the Microsoft Project Interface, uninstall the previous version. You can open a support ticket within your organization and ask a desktop administrator to assist you with the installation.

Manual Calculation in Microsoft Project

You can set the Calculation option in Microsoft Project to Off (manual), so that a CA Clarity PPM project is not recalculated when you open it in Microsoft Project. When you use manual calculation, Microsoft Project performs in these ways:

• Tasks are not adjusted or updated based on the dependency chain when you open a CA Clarity PPM project in Microsoft Project. The dependency chain becomes meaningless.
• Tasks remain stationary on the Gantt chart.
• You must schedule a project manually and shift the task dates.
• The project appears as it was last saved in CA Clarity PPM, provided you are not using CA Clarity PPM timesheets.
• The summary task is not calculated. The rolled up values of the child tasks are not displayed. As a result, the project level % Complete field in Microsoft Project may display an inaccurate value.

In the following example, the remaining work for Project 1 and Summary is not calculated and displays as zero hours. This happens because the project is not calculated when manual calculation is enabled.

Press F9 or use the Calculation Needed button in Microsoft Project to calculate the project. Microsoft Project calculates the plan and the rolled up values of all the tasks are displayed. Also, the tasks appear on the Gantt chart based on the Finish/Start dependency relationships.

Example: Tasks Remain Stationary on the Gantt Chart

When you enable manual calculation, tasks remain stationary on the Gantt chart and hours do not roll up to the summary task or project levels.

For example, enable manual calculation in Microsoft Project and also set the loading pattern to uniform in CA Clarity PPM. You then create a project in CA Clarity PPM with three tasks. Create a summary task and demote tasks as children under the summary task. Apply Finish/Start dependencies and identify remaining work and record actual work.

Open the CA Clarity PPM project in Microsoft Project. Because manual calculation is enabled, the project is not calculated and the results appear as shown in the following figure:

• The three tasks are stacked upon each other in the Gantt chart and do not appear based on the Finish/Start dependency links.
• The summary task displays zero for remaining work, actual work, and work instead of the sum of the tasks.
• The project may display incorrect values at the project or summary task levels.

  

Press F9 to calculate the project. The results appear as shown in the following figure:

• The three tasks are scheduled based on the dependency chain between them.
• The remaining work, actual work, and work for the summary task display the sum of the child tasks.

  

Example: Summary Task is Not Automatically Calculated

When you enable manual calculation, the summary task dates are not automatically calculated.

For example, enable manual calculation in Microsoft Project and also set the loading pattern to uniform in CA Clarity PPM. You then create a project in CA Clarity PPM with some tasks without dependencies. Create a summary task and demote tasks as children under the summary task. Drag the tasks manually on the Gantt chart to reflect the requirements of the project manager.

Open the CA Clarity PPM project in Microsoft Project. Because manual calculation is enabled, the project is not calculated and the results appear as shown in the following figure:

• In the Gantt chart, the Gantt line for the summary task reflects only one day instead of the range of the child tasks.

  

Press F9 to calculate the project. The results appear as shown in the following figure:

• The Gantt line for the summary task displays the date range of the child tasks.
• The summary task displays the rolled-up values.

  

Configuring Manual Calculation in Microsoft Project

For manual calculation to work, you must configure settings both in Microsoft Project and CA Clarity PPM in any order:

• Microsoft Project - Set the Calculation option to Off
• CA Clarity PPM - Set the loading pattern to uniform.

Set the Calculation Option in Microsoft Project

You must set the calculation option to Off in Microsoft Project. This setting is global and is saved in the .mpp file of each project. Any .mpp project that is created after configuring this setting inherits this setting.

Note: For .mpp projects that were created before configuring this setting, the project manager must update the global setting for that project. To update the global setting, open the plan in Microsoft Project from CA Clarity PPM and follow these steps.

Microsoft Project 2007

Follow these steps:

1. Open the Tools menu and click Options.
2. Click the Calculation tab.
3. Select Manual for Calculation mode in the Calculation options for Microsoft Office Project section.
4. Click OK.

Microsoft Project 2013 or 2010

Follow these steps:

1. Open File, Project Options, and then click Schedule.
2. Select Off for Calculate Project after each edit in the Calculation section.
3. Click OK.

Set the Loading Pattern in CA Clarity PPM

You must set the loading pattern to uniform using you administrator permissions.

Follow these steps:

1. Open Administration, and from Project Management, click Settings.
2. Set the Default Load Pattern as Uniform.
3. Click Save.

Microsoft Project Manual Calculation Exceptions

The following exceptions apply when manual calculation is enabled:

• CA Clarity PPM timesheets

  If you use timesheets, the actual hours that are recorded against tasks could override the configuration. The start date, finish date, or both can change.

  For example, Task 1 starts on May 1 and Ken records eight hours on April 20, a date before the task starts. The next time the project is opened in Microsoft Project, the start date of the task changes to April 20. The same is true if Ken records actual hours against the task after its finish date. Microsoft Project moves the finish date to the last recorded actual hours.

• Resource leveling

  Resource leveling also calculates the project. Do not use resource leveling if you do not want Microsoft Project to calculate your project.

• Task constraints

  Applying task constraints may trigger Microsoft Project to calculate the project even though the global setting for the Calculation option is set to Off.

Example: Resource Leveling in Microsoft Project

Resource leveling in Microsoft Project schedules the project based on the availability of the team members so that no resource is overallocated. Resource leveling delays tasks, splits tasks, and delays resource assignments to adjust the resource allocation. Resource leveling also calculates the project as it resource levels. Therefore, level the resources only if you want Microsoft Project to calculate your project.

Follow these steps:

1. Set the Calculation option in Microsoft Project to Off.
2. Create two tasks, Task1 and Task2.

   Microsoft Project automatically sets the start date for both the tasks to be today or the start date of the project depending on your Microsoft Project configuration.

3. Create a Finish/Start dependency between Task1 and Task2.

   The tasks remain stacked one upon the other indicating that the plan must be calculated.

   

4. Assign the same resource to each task.

   The tasks remain stacked one upon the other indicating that the plan must be calculated. As you can see below, the resource is expected to work 16 hours that day.

   

5. Manually level the resources.

   Microsoft Project automatically calculates or schedules the tasks so that the resource works eight hours a day of availability and therefore resolves overallocation. If you do not want the task positions to move, do not resource level.

   

Example: Task Constraints

When you apply task constraints, automatic calculation may be triggered even if the global setting is manual.

Follow these steps:

1. Set the Calculation option in Microsoft Project to Off.
2. Create a task, Task 1.

   Microsoft Project automatically sets the start date to be today or the start date of the project depending on your Microsoft Project configuration.

3. Move Task 1 to next Monday.

   Microsoft Project marks Task 1 with a Start No Earlier constraint. Hover over the Calendar icon to see this constraint.

4. Create another task, Task 2.

   Microsoft Project automatically sets the start date to be today or the start date of the project depending on your Microsoft Project configuration.

5. Move Task 2 to next Monday.

   Microsoft Project marks Task 2 with a Start No Earlier constraint. Hover over the Calendar icon to see this constraint.

6. Create a Finish/Start dependency between Task 1 and Task 2.

   When you create task constraints, Microsoft Project automatically calculates the tasks even though the global setting for the Calculation option is set to Off.

   

Example: Reconciling Resource Overallocation

The following example shows how reconciling resource overallocations manually does not trigger automatic calculation.

Follow these steps:

1. Set the Calculation option in Microsoft Project to Off.
2. Create two tasks, Task1 and Task 2.

   Microsoft Project automatically sets the start date to be today or the start date of the project depending on your Microsoft Project configuration.

3. Assign a resource to Task1.
4. Assign the same resource to Task2.
5. Create a Finish/Start dependency between Task1 and Task2.

   The tasks remain stacked one upon the other indicating that the plan must be calculated.

   

6. Drag Task 1 into Monday of the next week.

   The task remains frozen on the date you manually set indicating that the plan must be calculated.