Understanding Custom Fields in Microsoft Project

Microsoft Project allows users to create custom fields to store and calculate various project-related data. These fields can be either task-related or resource-related, enabling users to include data not inherently available in the program.

Creating Calculated Fields

1. Access the Custom Fields Box:
   • Click on the Project tab and navigate to the Properties group.
   • Select Custom Fields from the dropdown menu.
2. Choose the Field Type:
   • If the field is task-related, click on the Task button at the top.
   • If it’s resource-related, click on the Resource button.
3. Select the Field Type and Rename:
   • From the list on the right, select the field type you want to create (e.g., Number).
   • Click the Rename button to give your field a descriptive name.
4. Enter the Formula:
   • Click the Formula button to enter your formula.
   • Use the Function dropdown to find functions, such as DateDiff to calculate dates.

Example Formula: Number of Days Until Task Start

To calculate the number of days from today until the start date of each task:

Formula: =DateDiff("d", NOW(), [Start])

Using Functions in Microsoft Project

Microsoft Project supports various functions to be utilized within custom fields. Here are some essential functions:

• DateDiff: Calculates the difference between two dates in a specified interval.
• Hour: Returns the hour of the day from a given time.
• Minute: Returns the minute of the hour from a given time.
• IIf: Evaluates an expression and returns one of two values based on the result.
• IsDate: Checks if an expression can be converted to a date.

Example Formulas

Days Between Current Date and Task Finish Date

Formula: =DateDiff("d", NOW(), [Finish])

Status-Based Conditional Text

This formula checks the status of a task and returns corresponding text:

Formula: =IF([Status]="Late", "In Progress", IF([Status]="Future Task", "Incoming", IF([Status]="Complete", "Completed", "")))

Tips for Excel Users Transitioning to Microsoft Project

• Enclose field names with brackets when using them in formulas, e.g., [Status].
• Familiar functions like DateDiff and IIf are available in Project as they are in Excel.
• Test your formulas on sample tasks before applying them to your main project to ensure accuracy.