Local or Shared Repository?

While using QTP,usually we will be not able to decide whether to to use the Local object repository or shared object repositories.Well, here is a quick reference to decide..

This	In these situations...
local object repository	You are creating single-action tests. You are creating simple tests, especially under the following conditions: You have only one, or very few, tests that correspond to a given application, interface, or set of objects. You do not expect to frequently modify object properties. You are new to using QuickTest. You can record and run tests without creating, choosing, or modifying shared object repositories because all objects are automatically saved in a local object repository that can be accessed by its corresponding action.
shared object repository	You are creating tests using keyword-driven methodologies (not by recording). You have several tests that test elements of the same application, interface, or set of objects. You often work with multi-action tests and regularly use the Insert Copy of Action and Insert Call to Action options. You expect the object properties in your application to change from time to time and/or you regularly need to update or modify object properties. If you are familiar with testing, it is probably most efficient to save objects in a shared object repository. In this way, you can use the same shared object repository for multiple actions—if the actions include the same objects. Object information that applies to many actions is kept in one central location. When the objects in your application change, you can update them in one location for all the actions that use this shared object repository.

Courtesy: QTP Help