What is an eSignature in Maximo?  It is an electronic signature that consists of a user ID and a password known only to the user. It confirms that the person changing a record is the person who logged in to the system.

Go to Database Configuration and select the Object and Attribute that needs to have the E-signature enabled such as ASSET and attribute PRIORITY.  Click “View Details” in the Attributes section and check “E-signature enabled?” field.  Click Select Action -> Manage eSig Actions.  In “Application” section filter by the application name.  In “Options for Add to Bookmarks” section, choose the moment that you want to call the eSignature.  For example: “Save Asset”  If you choose “Save Asset” option, when you change a value in the field that you enabled eSignature and try to save this asset the eSignature dialog will appear.

Also check out: enabling Maximo audit tables. [IBM Support]