One of the greatest benefits of the logic model is that it clarifies what the program is. Understanding what the program is, is the first step in any evaluation.
What, in particular, do you want to evaluate? Is the focus of the evaluation the whole program or a component of the program? Perhaps you want to focus on the media campaign of your outreach program or one particular target group.
Programs are often complex. You may not have the resources or the need to examine everything. Use the logic model to select the particular aspect, depth, component, or parts you will evaluate.