Calculating Time Series Data

This chapter explains how to calculate time series data. For example, you can do inventory tracking by calculating the first and last values for a specific time period. You can also calculate period-to-date values.

This chapter includes the following sections:

Calculating First, Last, or Average Values

Using time balance and variance reporting tags on the dimension tagged as accounts, you can tell Essbase how to perform time balance calculations on accounts data.

Essbase usually calculates a parent in the dimension tagged as time by consolidating or calculating the formulas on the parent's children. However, you can use accounts tags, such as time balance and variance reporting tags, to consolidate a different kind of value. For example, if you tag a parent member in the accounts dimension with a time balance property of First, Essbase calculates the member by consolidating the value of the member's first child. For example, in the Sample Basic database, the Opening Inventory member in the Measures dimension (the accounts dimension) has a time balance property of First. This member represents the inventory at the beginning of the time period. If the time period is Qtr1, Opening Inventory represents the inventory available at the beginning of Jan (the first member in the Qtr1 branch).

To use accounts tags, you must have a dimension tagged as accounts and a dimension tagged as time. You use the First, Last, and Average tags (time balance properties) and the Expense tag (variance reporting property) only on members of a dimension tagged as accounts. The dimensions you tag as time and accounts can be either dense or sparse dimensions.

Note: If you are using Intelligent Calculation, changing accounts tags in the database outline does not cause Essbase to restructure the database. You may have to tell Essbase explicitly to recalculate the required data values. See Optimizing with Intelligent Calculation.

Specifying Accounts and Time Dimensions

When you tag a dimension as accounts, Essbase knows that the dimension contains members with accounts tags. When you tag a dimension as time, Essbase knows that this dimension is the one on which to base the time periods for the accounts tags.

In the Sample Basic database, the Measures dimension is tagged as accounts, and the Year dimension is tagged as time.

Figure 417: Sample Basic Outline Showing Accounts and Time Tags

For information on tagging accounts and time dimensions, see Setting Dimension and Member Properties.

Reporting the Last Value for Each Time Period

For an accounts dimension member, you can tell Essbase to move the last value for each time period up to the next level. To report the last value for each time period, set the member's time balance property as Last. (In the database outline, the TB Last tag is displayed.)

For example, in the Sample Basic database, the accounts member Ending Inventory consolidates the value for the last month in each quarter and uses that value for that month's parent. For example, the value for Qtr1 is the same as the value for Mar.

Figure 418: Sample Basic Outline Showing Last Tag

For information on tagging an accounts member as Last, see Setting Dimension and Member Properties.

By default, Essbase does not skip #MISSING or zero (0) values when calculating a parent value. You can choose to skip these values. See Skipping #MISSING and Zero Values.

Reporting the First Value for Each Time Period

For an accounts dimension member, you can tell Essbase to move the first value for each time period up to the next level. To report the first value for each time period, set the member's time balance property as First. (The tag displays as TB First in the database outline.)

For example, in the Sample Basic database, the accounts member Opening Inventory consolidates the value of the first month in each quarter and uses that value for that month's parent. For example, the value for Qtr1 is the same as the value for Jan.

Figure 419: Sample Basic Outline Showing First Tag

For information on tagging an accounts member as First, see Setting Dimension and Member Properties.

By default, Essbase does not skip #MISSING or zero (0) values when calculating a parent value. You can choose to skip these values. See Skipping #MISSING and Zero Values.

Reporting the Average Value for Each Time Period

For an accounts dimension member, you can tell Essbase to average values across time periods and consolidate the average up to the next level. For example, you can tell Essbase to average the values for Jan, Feb, and Mar and then use that value for the Qtr1 value. To report the average value for each time period, set the member's time balance property as Average.

For information on tagging an accounts member as Average, see Setting Dimension and Member Properties.

By default, Essbase does not skip #MISSING or zero (0) values when it calculates a parent value. Thus, when it calculates the average, Essbase aggregates the child values and divides by the number of children, regardless of whether the children have #MISSING or zero values. You can tell Essbase to skip #MISSING and zero values. See Skipping #MISSING and Zero Values.

Skipping #MISSING and Zero Values

You can tell Essbase how to treat #MISSING and zero (0) values when doing time balance calculations. A #MISSING value is a marker in Essbase that indicates that the data in this location does not exist, does not contain any meaningful value, or was never entered.

By default, Essbase does not skip #MISSING or 0 (zero) values when calculating a parent value.

You can override this default using the following tags:

To Perform This Task
Use this Tag

Skip #MISSING values when calculating a parent value

Skip Missing

In Outline Editor, select the parent member from the accounts dimension and click the button.

Skip 0 values when calculating a parent value

Skip Zeros

In Outline Editor, select the parent member from the accounts dimension and click the button.

Skip #MISSING values and 0 values when calculating a parent value

Skip Missing and Skip Zeros

In Outline Editor, select the parent member from the accounts dimension and click the button.



For example, if you tag an accounts dimension member as Last and Skip Missing, then Essbase consolidates the last non-missing child to the parent. Consider the following example:

Accounts -> Time
Jan
Feb
Mar
Qtr1

Accounts Member
(Last, Skip Missing)

60

70

#MI

70



Tagging an account as Average and Skip Missing may produce different results from tagging that account as Average and Skip None. A calculation performed with Average and Skip None will produce correct results because no data is skipped. But because grandparents with children are consolidated by summing the averages, results of a calculation on an account with Average and Skip Missing will be incorrect unless you use Dynamic Calc or Two Pass tags.

Considering the Effects of First, Last, and Average Tags

The following table shows how Essbase consolidates the time dimension based on the time balance (TB) First, Last, and Average tags on accounts dimension members.

Accounts -> Time
Jan
Feb
Mar
Qtr1

Accounts Member1

11

12

13

36

Value of Jan+Feb+Mar

Accounts Member2
(TB First)

20

25

21

20

Value of Jan

Accounts Member3
(TB Last)

25

21

30

30

Value of Mar

Accounts Member4
(TB Average)

20

30

28

26

Average of Jan, Feb, Mar



Placing Formulas on Time and Accounts Dimensions

If you place a member formula on a time or accounts dimension, it may be overwritten by a time balance calculation.

Consider the following example from Sample Basic, in which Opening Inventory is tagged as First:

Measures -> Year
Jan
Feb
Mar
Qtr1

Opening Inventory: First

30000

28000

27000

30000



Because Opening Inventory is tagged as First, Essbase calculates Opening Inventory for Qtr1 by taking the Opening Inventory for Jan value. Any member formula that is placed on Qtr1 in the database outline is overwritten by this time balance calculation.

Calculating Period-to-Date Values

You can calculate period-to-date values for your data. For example, you can calculate the sales values for the current quarter up to the current month. If the current month is May, using a standard calendar quarter, the quarter total is the total of the values for April and May.

In Essbase, you can calculate period-to-date values in two ways:

This section explains how to use Dynamic Time Series members to dynamically calculate period-to-date values. Using Dynamic Time Series members is the most efficient method in almost all cases. For an example using the @PTD function to calculate period-to-date values, see Examples of Formulas.

Using Dynamic Time Series Members

In order to calculate period-to-date values dynamically, you need to use a Dynamic Time Series member for a period on the dimension tagged as time. See Specifying Accounts and Time Dimensions.

You do not create the Dynamic Time Series member directly in the database outline. Instead, you enable a predefined Dynamic Time Series member and associate it with an appropriate generation number. This procedure creates a Dynamic Time Series member for you.

For example, if you want to calculate quarter-to-date values, you enable the Q-T-D member and associate it with the generation to which you want to apply the Dynamic Time Series member. In Sample Basic, this is generation number 2, which contains the Qtr1, Qtr2, Qtr3, and Qtr4 members. Essbase creates a Dynamic Time Series member called Q-T-D and associates it with generation 2. The Q-T-D member calculates monthly values up to the current month in the quarter. For more information, see Enabling Dynamic Time Series Members.

Figure 420: Sample Basic Outline Showing Time Dimension

Dynamic Time Series members are not displayed as members in the database outline. Instead, Essbase lists the currently active Dynamic Time Series members in a comment on the time dimension. In the following outline, H-T-D (history-to-date) and Q-T-D (quarter-to-date) are active. H-T-D is associated with generation 1; Q-T-D is associated with generation 2.

Figure 421: Sample Basic Outline Showing Dynamic Time Series

Essbase provides eight predefined Dynamic Time Series members:

H-T-D

History-to-date

Y-T-D

Year-to-date

S-T-D

Season-to-date

P-T-D

Period-to-date

Q-T-D

Quarter-to-date

M-T-D

Month-to-date

W-T-D

Week-to-date

D-T-D

Day-to-date



These eight members provide up to eight levels of period-to-date reporting. How many members you use and which members you use depends on your data and your database outline.

For example, if your database contains hourly, daily, weekly, monthly, quarterly, and yearly data, you might want to report day-to date (D-T-D), week-to-date (W-T-D), month-to-date (M-T-D), quarter-to-date (Q-T-D), and year-to-date (Y-T-D) information.

If your database contains monthly data for the past 5 years, you might want to report year-to-date (Y-T-D) and history-to-date (H-T-D) information, up to a specific year.

If your database tracks data for seasonal time periods, you might want to report period-to-date (P-T-D) or season-to-date (S-T-D) information.

You can associate a Dynamic Time Series member with any generation in the time dimension except the highest generation number, irrespective of the data. For example, if you choose, you can use the P-T-D member to report quarter-to-date information. You cannot associate Dynamic Time Series members with level 0 members of the time dimension.

Enabling Dynamic Time Series Members

To use Dynamic Time Series members, you need to enable them. If required, you can specify aliases for Dynamic Time Series members. See Specifying Alias Names for Dynamic Time Series Members.

To enable Dynamic Time Series members using Application Manager:

  1. In Outline Editor, open the database.
  2. Select Outline > Dynamic Time Series.
  3. Essbase displays the Dynamic Time Series Member Information dialog box.

    Figure 422: Dynamic Time Series Member Information Dialog Box for Sample Basic

  4. In the DTS Member list, select the required Dynamic Time Series member. For example, select Q-T-D (quarter-to-date).
  5. In the Generation list, select the appropriate generation number. For example, in the Sample Basic database, select generation 2 to associate the Q-T-D member with that generation.
  6. Note: How many generations the Generation list displays depends on how many generations are in the time dimension. You cannot associate Dynamic Time Series members with the highest generation (level 0 members).

  7. Check Enable This DTS Member.
  8. In Sample Basic, the DTS member may already be enabled by default.

    Figure 423: Dynamic Time Series Member Information Dialog Box Showing Q-T-D on Sample Basic

  9. If desired, you can create an alias name for the DTS member. See Specifying Alias Names for Dynamic Time Series Members.
  10. To enable the Dynamic Time Series member, click OK.
  11. In the database outline, Essbase adds a comment to the dimension tagged as time. Figure 424 shows the Sample Basic database with H-T-D and Q-T-D defined.

    Figure 424: Sample Basic Outline Showing Dynamic Time Series Members

Disabling Dynamic Time Series Members

To disable a Dynamic Time Series member, you tell Essbase not to use the predefined member.

To disable a Dynamic Time Series member using Application Manager:

  1. In Outline Editor, open the database.
  2. Select Outline > Dynamic Time Series.
  3. Essbase displays the Dynamic Time Series Member Information dialog box.

  4. In the DTS Member list, select the Dynamic Time Series member you want to disable.
  5. Figure 425: Dynamic Time Series Member Information Dialog Box Showing Enabled Q-T-D

  6. Clear Enable This DTS Member.
  7. Figure 426: Dynamic Time Series Member Information Dialog Box Showing Q-T-D Disabled

  8. Click OK.

Specifying Alias Names for Dynamic Time Series Members

You can specify alias names for predefined Dynamic Time Series members. You can then use the alias names to retrieve the Dynamic Time Series members in Spreadsheet Add-in or in a report.

You can create up to eight alias names for each Dynamic Time Series member. Essbase saves each alias name in the Dynamic Time Series alias table that you specify.

To specify an alias name for a Dynamic Time Series member:

  1. In the Dynamic Time Series Member Information dialog box, enable the DTS member. See Enabling Dynamic Time Series Members.
  2. In the Alias Table list, select the alias table in which you want to save the alias name.
  3. In the Alias text box, type the alias name for the DTS member.
  4. For example, type QtrToDate.

    Figure 427: Dynamic Time Series Member Information Dialog Box Showing Q-T-D Alias

  5. Click Set.
  6. To save the alias name to the chosen alias table, click OK.

For more information on specifying and displaying alias names, see Creating and Changing Database Outlines.

Applying Predefined Generation Names to Dynamic Time Series Members

When you enable a Dynamic Time Series member and associate it with a generation number, Essbase creates a predefined generation name for that generation number. These generation names display in the Generation and Level Names dialog box. To open this dialog box, select Outline > Gen/Level Names in Application Manager Outline Editor. For more information on creating generation names, see Creating and Changing Database Outlines.

This table shows the Dynamic Time Series members and their corresponding generation names:

Member
Generation Name
Member
Generation

H-T-D

History

Q-T-D

Quarter

Y-T-D

Year

M-T-D

Month

S-T-D

Season

W-T-D

Week

P-T-D

Period

D-T-D

Day



These member and generation names are reserved for use by Essbase. If you use one of these generation names to create a generation name on the time dimension, Essbase automatically creates and enables the corresponding Dynamic Time Series member for you.

For example, in Sample Basic, you can create a generation name called Quarter for generation number 2. Quarter contains quarterly data in the members Qtr1, Qtr2, and so on. When you create the generation name Quarter, Essbase creates and enables a Dynamic Time Series member called Q-T-D.

Retrieving Period-to-Date Values

When you retrieve a Dynamic Time Series member, you need to tell Essbase the time period up to which you want to calculate the period-to-date value. This time period is known as the latest time period and must be a level 0 member on the time dimension.

To specify the latest time period:

The member-specific setting-for example, Q-T-D(May)-takes precedence over the <LATEST or Latest Time Series option setting.

The following example shows Sample Basic data. Q-T-D(May) displays the period-to-date value for May that is obtained by adding the values for Apr and May (8644 + 8929 = 17573):

Figure 428: Spreadsheet Add-in Showing Period-To-Date Value for May

Using Dynamic Time Series Members in Partitions

If Dynamic Time Series members are part of the shared area between databases, you need to define the Dynamic Time Series members in both databases, just as you would for regular members. For example, if your partition definition includes Qtr1, Qtr2, Qtr3, Qtr4, and the Dynamic Time Series member Q-T-D, then you need to define the Q-T-D member in both the source database and the target database.

If a Dynamic Time Series member is not part of the shared area between databases, Essbase gets the data for that member from the source database. You do not need to define the Dynamic Time Series member in both databases. However, this configuration is generally less efficient than including the Dynamic Time Series member in the partition definition.

For more information on partitioning, see Building and Maintaining Partitions.




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