Choosing Application Recognition Rules
In addition to the application definitions which are regularly updated with new versions of Vector AM, the Software Identification Manager enables you to create new definitions to identify any software used by your organization. Use the following tips to help optimize your own application definitions:
Use application-specific names
The easiest way to identify an application is to check for the presence of files it installs. Choose filenames that are application-specific. For example, PRINT.DLL could be a component of any application, but WINWORD.EXE is specific to Microsoft Word. Similarly, if an application always creates its own subdirectories as part of an installation, you can create rules that check for the directory rather than a specific file.
Choosing unique files and placing them at the top of the application definition helps reduce the scope for recognition failures and increases the efficiency of software inventory operations.
Avoid too many file rules
Using too many files rules can restrict the application definition to one installation of an application and cause recognition failures for installations that are only slightly different. For example, checking for an optional component, such as TUTORIAL.HLP, may prevent Vector AM from recognizing an application when the file is not installed on all Clients.
Check whether the application manufacturer specifies the version number of the application in the timestamps, datestamps, or version information properties of the application files. If they have, you can use the Add Version Rule option to extract the version information and automatically keep the application definition up-to-date without the need to extend the application definition whenever a new version of the application is released.
Use flexible file property checks
Using precise file size checks, rather than size ranges, can cause a recognition failure when an application variant is installed. For example, applications that are shipped in multiple language variants often differ in size between the US English and the International English versions. Similarly, vendor-supplied patches can include new versions of files with sizes that are not the same as the original installation. Using a size range can help you produce application definitions that reliably identify new versions of application versions.
Sometimes an application version can be identified by the addition of completely new files or directories. You may be able to check for a file which was not present in previous versions rather than becoming reliant on a size change in one application file.
Use optional rule blocks to test for application versions
Normally, all tests within an application definition must be passed to successfully identify an application. However, rules embedded within option rule blocks do not cause recognition failures. This enables you to create general rules to identify all versions of an application using a few simple file tests, and then to create a series of more complex optional rule blocks that identify specific versions. For example, using this technique, the Microsoft Word definition in the Applications Library first identifies the Word using a file rule to test for the main executable file, and then it attempts to identify the Word version using more specific rules, such as size checks, in optional blocks. This ensures Word is identified even when there is no version rule for the WINWORD.EXE that has been detected.