The two most important components are the Scope Definition and the Work Breakdown Structure, or WBS, for controlling and managing a successful project. These two components will be used throughout your entire project to ensure that all your work gets completed. They will act as control mechanisms throughout the project to ensure the success of the project.
Every project starts with a Scope Statement. The Scope Definition then elaborates this Scope Statement on. The Scope Definition divides the Scope Statement into major deliverables. These major deliverables are then broken down into the WBS. The WBS is a complete checklist of all the work that must be done so the project can be completed successfully. High-level categories of work are broken down into activities or tasks. Activities or tasks are then further broken down so you can assign a reasonable level of work effort to each activity or task. Many project management professionals use the 80-hour rule.
You can then apply resources, dates, and cost and assign an estimate to your activities or tasks once you have created the WBS. Some of the more common estimating techniques are Analogous (Top Down), Delphi (Bottom Up), and Program Evaluation and Review Technique (P.E.R.T.). Project management models utilize these estimating techniques to improve the accuracy of initial work effort estimates to shrink the variance gap between baselines and actual schedule and cost.
A Responsibility Assignment Matrix (RAM) has various names, but all with the same purpose: to clarify and link resources to the Scope Definition and WBS. It is important to determine the level of involvement and responsibility of that work by each resource as roles and responsibilities are assigned to various work assignments on the project. For example, both the Project Sponsor and the Project Manager are responsible for the projects success, but at different levels. These levels may be defined by who actually does the work, who has input, who is informed, and who approves or signs off on that work.
In plain English; Each individual must sign off and take responsibility for their part in the project. Each project sector must start when scheduled, finish on time and stay within budget.