Evaluating Retention Rules

Since each ILM policy for an ILM object refers to exactly one audit area, it is possible for multiple ILM rules to be defined for an ILM object in different audit areas. When evaluating ILM rules for an ILM object, the system determines the start and end dates of the minimum and maximum residence periods. The rule simulation log differentiates between the following types of rules:

Valid rules that correspond to the conditions entered
Operative rules that affect the determination of the retention period

Determining the Operative Retention Periods

To determine operative rules and, thereby, the minimum and maximum retention periods (the start and end dates of both), the system proceeds as follows:

Reads all productive policies
Evaluates all valid rules in each live policy (the rules with the highest priority) and in all audit areas for calculating the following values for each rule:
- Start date (based on the method for start date determination defined in Customizing)
  For more information, see: Explicit and Implicit Start Date Determination
- End date (start date plus duration)
Determining the operative rules according to the following principles:
- The rule that supplies the latest end date for the minimum retention period, determines the following:
  - End date of the minimum retention period
  - Start date of the minimum and maximum retention periods
  - Assignment of the ILM store
- The rule that supplies the earliest end date for the maximum retention period, determines the end date of the maximum retention period.

The following figure describes how to determine the start and end dates for the minimum and maximum retention periods of an ILM object instance.

This graphic is explained in the accompanying text.

Determining the retention period based on multiple ILM rules

Valid Rule	Result of the Rule	Operative Result	Effect on Data Retention
Rule 1	Earliest end date of the maximum retention period (end max)	End date of the maximum retention period	Retention is legally prohibited as of the end date of the maximum retention period. If there are no more retention requirements, the data object must be destroyed.
Rule 2	Latest end date of the minimum retention period (end min)	Start date of the entire retention period End date of the minimum retention period ILM Store	Within in minimum retention period, the data must be retained according to legal requirements. This is also true if the maximum retention period is shorter. If the maximum retention period is longer, then the data has to be destroyed at the end of this period.
Rule 3	End date of the minimum retention period is before the operative end date supplied by rule 2. End date of the maximum retention period is after the operative end date supplied by rule 1.	No operative result	No effect

Effect of the Maximum Retention Period

As the system evaluates all ILM policies for all audit areas to which the ILM object belongs, it is possible that the maximum retention period (data destruction mandatory) is longer or shorter than the minimum retention period (data destruction permitted9. The following figures illustrates both of these cases.

This graphic is explained in the accompanying text.

Effect of the maximum retention period on data retention

Maximum Retention Period	Effect on Data Retention
LONGER than the minimum retention period	Data retention is required only up to the end of the minimum retention period (end of the retention requirement). Data destruction is permitted at this time. Retaining data until the end of the maximum retention period is optional. Data destruction is required after this time.
SHORTER than the minimum retention period	At the end of the maximum retention period, the data destruction is required. However, an additional retention requirement exists up to the end of the minimum retention period, data destruction is not permitted until after this time. When the application supports the authorization-dependent display of data, you could control access to the data after the end of the maximum retention period as follows: Data is always locked (cannot be displayed) Up until the permitted destruction date (end of the minimum retention period), only persons responsible, such as tax auditors, have access to the data.

Maximum Retention Period

Effect on Data Retention

LONGER than the minimum retention period

Data retention is required only up to the end of the minimum retention period (end of the retention requirement). Data destruction is permitted at this time.

Retaining data until the end of the maximum retention period is optional. Data destruction is required after this time.

SHORTER than the minimum retention period

At the end of the maximum retention period, the data destruction is required. However, an additional retention requirement exists up to the end of the minimum retention period, data destruction is not permitted until after this time.

When the application supports the authorization-dependent display of data, you could control access to the data after the end of the maximum retention period as follows:

Data is always locked (cannot be displayed)
Up until the permitted destruction date (end of the minimum retention period), only persons responsible, such as tax auditors, have access to the data.