The Estimates by Period tab is available if the Estimates by Period check box is selected on the Main tab. The nested tabs appear in accordance with the selected estimation method. For the Calculation of Revenue Based on Costs estimation method, the following nested tabs are available: Revenue and Costs and Overhead.
On the Estimates by Period tab, you can view the project's duration as specified on the Main tab and you can select project's planning period. The data from the Revenues and Costs and Overhead tabs can be distributed between the periods manually or automatically (evenly by day, that is, proportionally to period durations in days).
The "Project Estimates (create)" form. The Estimates by Period tab
You can use the Project Planning Period field to select the planning period (interval) for the project from the following options:
- Week: To use calendar weeks as planning periods. Calendar week starts from Sunday and ends on Saturday. If a project starts not on Sunday, Week 1 will have less than 7 days.
- Month: To use calendar months as planning periods. Calendar months differ in duration, and project periods will have different numbers of days accordingly. If a project starts on other than 1st day, the first period will have less days.
- Quarter: To use calendar quarters as planning periods. Calendar quarters starts on January 1, April 1, October 1
- Half Year: To use calendar half years as planning periods.
- Year: To use calendar years as planning periods.
Note. Generally, the periods of any of the selected type may not have equal durations, because they must match the calendar. For example, for a project with start date on Wednesday, February 3, the selected planning period of Week means that Week 1 will start on February 3 and will last 5 days, while Week 2 will last 7 days. The same for other types of planning periods.
Then, you can use the nested tabs: Revenue and Costs, Overheads to allocate the estimated amounts to periods.
The nested Revenue and Costs tab
Using the Revenue and Costs tab, you can specify the revenue and cost amounts planned in specific periods. This tab contains two panes: Revenues and Costs.
Note. For each revenue there can be multiple costs in the Costs pane. You can choose to view all costs at one, or you can select the Show costs for the selected revenue only check box at the form bottom to view in the lower pane only the costs associated with the revenue selected in the upper pane.
The Revenues pane
The project's revenue estimates were created for combinations (sets) of the analytical parameters selected from the following ones for this particular project: Project Task, Item, Company, Business Activity, Department, and Income Item. The corresponding columns are populated from the Revenue pane on the Revenue and Costs tab.
The Total Estimated Amount column shows the revenue amount estimated for the project's entire duration.
Under the Allocated by Period heading, there are two columns, % and Amount, for each period within the project duration. You can enter the percentages or amounts for periods manually or click the Fill button to allocated the amounts evenly by number of days. Make sure that the resulting sum of percents is 100%, or the sum of amounts is equal to amount in the Total Estimated Amount column.
The Total Allocated amount column shows the resulting sum of the amounts allocated to periods. The Not Allocated Amount column shows the difference between the estimated and allocated amounts. Generally, it should be 0.
The Costs pane
The project's cost estimates were created for combinations (sets) of the analytical parameters selected from the following ones for this particular project: Project Task, Cost Element, Business Activity, Department. The Expense Item is required. The corresponding columns are populated from the Costs tab.
The Total Estimated Amount column shows the cost estimated for the project's entire duration.
Under the Allocated by Period heading, there are two columns, % and Amount, for each period within the project duration. You can enter the percentages or costs and expenses for periods manually or click the Fill button to allocate the amounts evenly by number of days. Make sure that the resulting sum of percents is 100%, or the sum of amounts is equal to amount in the Total Estimated Amount column.
The Total Allocated amount column shows the resulting sum of the cost and expense amounts allocated to periods. The Not Allocated Amount column shows the difference between the estimated and allocated amounts. Generally, it should be 0.
The nested Overheads tab
Using the Overheads tab, you can specify the overhead costs planned in specific periods. 
he "Project Estimates (create)" form. The Estimates by Period (Overhead) tab
The project's overhead estimates as well as cost estimates were created for combinations (sets) of the analytical parameters selected from the following ones for this particular project: Project Task, Cost Element, Business Activity, Department. The Expense Item is required. The corresponding columns are populated from the Overhead tab.
The Total Estimated Amount column shows the overhead amount estimated for the project's entire duration.
Under the Allocated by Period heading, there are two columns, % and Amount, for each period within the project duration. You can enter the percentages or amounts for periods manually or click the Fill button to allocated the overhead costs evenly by number of days. Make sure that the resulting sum of percents is 100%, or the sum of amounts is equal to amount in the Total Estimated Amount column.
The Total Allocated amount column shows the resulting sum of the amounts allocated to periods. The Not Allocated Amount column shows the difference between the estimated and allocated amounts. Generally, it should be 0.