Planning is the first phase in developing a CCPM driven project. The CCPM methodology offers a unique optimization technique that allows your project manager to plan and determine the critical chain, which is actually a set of resource-dependent tasks having a greater impact to the completion date of your project (such tasks have the longest possible duration). Such a technique entails performing a resource-leveling activity that looks at individual tasks and identifies which of these tasks can be done with shortened durations. Critical chain optimization also focuses the project manager on resource planning activities to keep project resources smoothly and evenly loaded among individual tasks.
The Planning phase of the methodology requires setting up the entire safety margin for the project schedule in order to minimize the ability of shortening the overall project duration. However, such a margin does not mean that there is no risk of breaking time estimates per critical task. Note that it just minimizes the probability of occurring critical tasks exceeding their estimated lengths.
If to be more specific, successful implementation of the Planning phase requires your project manager to schedule buffers for ensuring success of critical chain tasks. It actually means that there is a high-level process to complete the phase. Such a process is called "Scheduling buffers".
The process can be divided into a number of tasks that are easier to plan and manage. With help of VIP Task Manager you can carry out the Planning phase, its process and tasks. The software allows developing to-do lists, templates and task hierarchies. Let’s find out what tasks are sample to the process and how VIP Task Manager can be helpful for managing such tasks.
The CCPM methodology adds specific safety margins or buffers (blocks of time protecting due dates from delays) to the project schedule. Buffering (that’s a process of defining and setting buffers) lets push individual and resource-dependent tasks to their completion in the shortest time possible. Buffering is a safety mechanism that helps you manage the impact of uncertainty and variation to a deliverable of your project. Using buffers in the schedule means placing strategic points necessary to ensure success of critical chain tasks; hence buffers allows for your project to reach sufficient safety levels.
There are four types of buffers such as project buffer, feeding buffer, resource buffer, and capacity buffer. Let’s describe each of the buffer types.
- Project Buffer. The project buffer is placed between the final scheduled task of the critical chain and the estimated project end-date. It helps protect your project from delays and missed end-dates due to variations among critical chain tasks. The project buffer allows using a portion of the safety margin time removed from every task estimate to create a joined buffer task. It actually means that an amount of time when individual tasks are uncertain is buffered. The critical chain starts at the project start time and ends at the beginning of the project buffer.
- Feeding Buffer. Adding such a buffer to the schedule makes it possible to avoid situations when missed completion dates of non-critical chain tasks have an impact to individual tasks of the critical chain. The feeding buffer is a portion of time at those points in the schedule where non-critical tasks merge with critical chain tasks. Hence, the feeding buffer isolates completion time of critical chain tasks from non-critical tasks.
- Resource Buffer. It is a portion of time required by critical resources to complete their critical chain tasks. The resource buffer ensures coherence elements of the critical chain. It means that when a critical chain task is completed, the next task scheduled in the critical chain should be started.
- Capacity Buffer (optional). This type of buffers assumes that for a multi-project environment there is a need to plan for on-call resources by adding more costs covering the resources to the overall budget. In such a way, you can allocate an amount of money for using on-call resources in cases when there’re schedule delays due to unforeseen issues. If you manage a single project, there’s normally no need to schedule the capacity buffer.
The Planning phase requires the project manager to define these buffers before project work is started. Reviewing and control of the buffers will be conducted by the manager during the Monitoring phase. The buffers are also used during the Execution phase when the manager needs to do work according to the original schedule. They help efficiently analyze current progress of the project, implement corrective actions, and detect any delays occurring in the schedule.
Using VIP Task Manager
It is convenient to organize the process of buffer scheduling into a range of tasks by using VIP Task Manager. The software features Task Tree view that allows you to design a hierarchy of tasks and groups to plan the process. Below you can see sample tasks that describe the buffer scheduling process and the Planning Phase as well.
- Define an amount of work required for delivering your project
- Estimate the completion date for the project
- Estimate the start date for the project
- Decompose work into simple, measurable tasks
- Develop a project plan showing how tasks are organized and performed
- Assign resources to tasks
- Assign duration to every task
- Define those tasks having the longest durations
- Combine the tasks into the critical chain (meaning these tasks cause the longest duration for the whole project)
- Define the critical resources (those resources assigned to the critical chain tasks)
- Develop a schedule for the project
- Place the project buffer on the schedule between the final scheduled task of the critical chain and the estimated project completion date.
- Add the feeding buffer to the schedule by defining periods of time when the critical chain tasks overlap with non-critical tasks.
- Schedule the resource buffer by estimating time required for the resources to complete tasks of the critical chain.
- Define the capacity buffer by allocating more funds to on-call resources.