Make the Budget field visible & accessible to the user:
- From Setup click the Object Manager tab, select Opportunity
- Navigate to Fields & Relationships and open Budget field
- Select “set field level security” button
- Make sure that all boxes are checked in the Visible column
- Only de-select the System Admin in the Read-only column
- Click Save. This allows the Budget field to be editable by end users.
Add Budget field to the Opportunity page layout:
- From Setup click the Object Manager tab, select Opportunity
- Navigate to Page Layouts
- Select page layout, drag & drop to the field to the Opportunity detail section
- Click Save
Create a rule to populate the budget field with 10% “spend budget” of the Opportunity value:
- From Setup navigate to Workflow Rules, click Continue if the "Understanding Workflow" message appears. Then click the "New Rule" button
- Create a new rule
- Select the Object you wish to set a budget on and click next. In this example the Opportunity budget.
- Fill out the form like this:
- Rule name: "Set Budget to 10% of Opp Value"
- Description: Automatically sets Opp "budget" to 10% of opportunity value so that expenses against this object are drawn-down against budget to help with planning and forecasting spend.
- Evaluation Criteria: Created & every time it’s edited
- Rule Criteria: Run this rule if the formula evaluates to true
- Copy this Formula: ISNEW() || ISCHANGED(Amount)
Save
Add Workflow Action named: Update Budget Field
- Unique name: Update_Budget_Field
- Description: Calculate Budget as 10% of Opp value when Opp Amount is new or changed.
- Check the box to: Re-evaluate Workflow Rules after Field Change
- Specify new value Use a Formula to set new value:
- Save => Done => Activate.
Check your work: open an Opportunity. Update the Opp Value & corresponding 10% budget will be assigned. See if that value is in the budget field. Modify the opp value. Ensure the budget field updates accordingly to 10% of the new value.
Need more information? Please refer to Salesforce documentation.