Assumptions reflect our recognition that there are factors beyond our control that are necessary for successful achievement of objectives at all levels of the project. The project design team must do its best to identify and assess critical assumptions. Major assumptions, risks, and contingencies should be assessed with project feasibility in mind.

In an Objective Tree, "if-then" hypotheses are show as a hierarchy that leads from Outputs to a Project's Goal. This hierarchy is incorporated into a Logical Framework's Narrative Summary column. While the reasoning in this first column of a Logical Framework captures key elements of what is necessary to achieve an important set of results, this picture is often incomplete.

Beyond a chain of intended results lies a set of conditions about which designers make assumptions that must also be valid for project results to be achieved. The Logical Framework demands transparency about these other factors. The matrix calls for their disclosure at every level of a results hierarchy, so that it is clear what risks might exist with respect to achieving a project's Purpose. The Assumptions column at the far right of a Logical Framework matrix documents these other factors. Together, the Narrative Summary and Assumptions columns of a Logical Framework tell us what the necessary and sufficient conditions are for success.

In the table below, the Narrative Summary of project hypotheses and results for a trade facilitation project is shown next to assumptions that a design team might have made for this project. The figure brings together the far left and right columns of a Logical Framework matrix as if the middle columns had been folded away to display bones of the project's design logic clearly. Arrows on the diagram illustrate how these two columns are to be read.