Time - The amount of time necessary to complete the project. Normally, it is divided for analysis in the time necessary to complete the project components. This is further broken down in the time necessary to complete each task of contributing to the completion of each component.
Quality - The amount of time put in to individual tasks determines the overall project quality. Some tasks may need a definite amount of time to complete adequately, but more time could be done exceptionally. During a large project, quality can have a significant impact on the time and cost (or vice versa).
Cost - Calculated from the time variable. Cost for development of an internal project is time multiplied by the cost of team members. When hiring an independent consultant for a project, the cost will typically be determined by the consultant or firm per hour multiplied by an estimated time to complete.
Scope - requirements specified for the final result. The general definition of what the project must meet, as well as a specific description of what the finish result should be or over out.
Risk - potential points of failure. Most risks or potential failures can be overcome or resolved, given time and resources.
Four of these variables can be given by external or internal customers. The value (s) of the remaining variables are then set by project management, ideally based on robust estimation techniques. The final values must be agreed in a negotiation process between project management and client. In general, values are employed in terms of time, cost, quality and scope.To maintain control over the project from the beginning of the project to reach its natural conclusion, a project manager uses a quantity of techniques: project planning, earned value, risk management, planning and process improvement.