To analyze a schedule is beneficial to understand and organize a project. Project schedules, in which time plans are created based on the Critical Path Method (CPM) or on Resource-Constrained Project Scheduling Problem (RCPSP) optimization, are targets herein. According to the concepts of the Theory of Constraints (TOC), a schedule is treated as a system. Schedule elements are suspected constraints. Moreover, a goal depends on the policy of schedule creation. Schedules are further analyzed herein to recognize its bottlenecks. Additionally, resource information is surveyed to identify true constraints. To integrate identified constraints on a schedule, a framework is proposed and the concept named the critical resource chain is introduced. Three scenarios are employed to illustrate the proposed framework under different scheduling considerations. Issues of project understanding can then be explained and discussed through identified constraints.