Inventory rules evaluate the software that is installed on a client computer and the client computer's environment. You can associate a software resource with the following types of inventory rules:
Determine if specific software is installed on a client computer. A detection rule ensures that Software Discovery can detect an installed software resource that is EXE based and add it to the Newly Discovered Software list. A detection rule must also be associated with an EXE based software resource for a compliance check in a Managed Software Delivery to report success.
A detection rule can look for information such as the file associations, MSI product code, shortcuts, and registry entries.
For example, when you define a software resource, you can associate it with one or more files that represent it. A detection rule looks for the presence of those files on the client computer. If it finds those files, then it assumes that the software resource is installed.
Determine whether a client computer has the correct environment for an installation of the software.
An applicability rule can look for information such as the operating system, processor type, Windows language, and registry entries.
For example, if the software requires a specific operating system, the applicability rule checks the client computer for the presence of that operating system.
The detection rules and the applicability rules help the software-related operations to identify software resources accurately.
Examples are as follows:
In Software Management Solution, a Managed Delivery policy uses an applicability rule to determine whether the software can be installed on the client computer. If the client computer has the correct environment, the Managed Delivery policy uses a detection rule to determine whether the software is already installed. If the software is not installed, then the policy installs it. The use of the detection rule prevents you from reinstalling the software on the computers that already have that software.
In Inventory Solution, the Targeted Software Inventory policy uses a detection rule to determine whether a specific software resource is installed on client computers. The policy then reports the computers that contain the software.
In Patch Management Solution, the Inventory Rule policy periodically inventories operating systems, applications, and installed patches on managed computers. The policy detects vulnerabilities to known Microsoft security problems. This information is used to determine which software updates a managed computer requires.
Some rules, such as those that Patch Management Solution uses, can be predefined. Otherwise, you create the rules that you need for each software resource. Other internal products or third-party products can be programmed to create and use detection and applicability rules.
If you want to delete a detection rule or applicability rule that you created, you must delete it from the All Resources view. The detection rules and applicability rules are listed at All Resources > HashedResource > Inventory Rule. By default, these resources do not appear in the All Resources view. You can display these resources by selecting the Default view and clicking Filter in the right pane.
UNIX, Linux, and Mac OS operating systems do not support detection and applicability rules; therefore, do not add them to non-Windows software resources. When you add rules to non-Windows software resources, the rules are always evaluated as false, which can cause errors in your software-related operations.