Theory of Constraints Handbook - James Cox Iii [72]
5. As in-process projects are completed, release the on-hold projects one by one according to their established priority.
Avoid paralysis by analysis. The goal is to get results quickly. For example, a major pharmaceutical company almost doubled its rate of project completion in the first 8 weeks—following the implementation of this step, they finished 11 projects compared to 6 projects in the prior 8 weeks. In other cases of comparable potential, hesitancy led to “more study,” initial enthusiasm and momentum were lost, and the implementations were subsequently abandoned.
Step 3: Build Buffered Project Plans
Project plans are needed to provide execution priorities and early warning signals, and require the following data:
Tasks and dependencies (precedents and hand-offs) among tasks
Duration of tasks
Type and quantity of resources needed for each task
Task managers
Buffers (feeding buffers, contractual milestone buffers, and project buffers)
Resource types and the maximum units of a resource type available to the project
Project end date and contractual milestone dates
While the concept of a project plan is simple, many organizations struggle with defining the right level of detail.
Degree of Detail Required in the Plans
Too many tasks in a project plan induce multitasking, make it difficult to analyze plans and buffer consumption, and generally lead to loss of control. Not enough detail, on the other hand, leads to unclear priorities and hence the same effects.
Based on evidence from a wide range of industries, a task should be 3 to 7 percent of a buffered project’s lead time. More than 250 to 300 tasks in a complex project and less than 10 to 15 tasks in a simple project are not recommended. If this guideline yields tasks that are too long and thus not useful for task managers, then subprojects can be used to zoom into detailed tasks instead of adding tasks to the main project. Subprojects that are two to four weeks long can be a network of tasks without buffers, while longer subprojects must be properly buffered project plans. For reference purposes:
An IT application development project with 200 people working on it for four months is executed successfully with 150 tasks.
Aircraft maintenance and repair projects with 50,000 hours of work per project and durations of 7 months are managed with less than 200 tasks.
A 3-year pharmaceutical research and development project, with about 50 scientists and professionals working on it, could be managed well with about 175 tasks in the main project.
Development of digital cameras with 100 engineers and 10 projects at a time could be managed with 150 tasks per project.
Ten-day long helicopter maintenance and repair projects requiring about 4500 hours of work are being managed with 15 tasks.
Commercial shipbuilding projects with 750 people working on a project for one year are being managed with 275 tasks.
Construction of five 50-story buildings with 1600 people working on them for three years was managed with 5 projects and 290 tasks in each project.
The Process of Creating Buffered Project Plans
1. Define cycle-time targets.
2. Communicate to all managers that people will not be measured in execution against the task estimates used in planning.
3. Assemble a team of representative project managers and task managers and conduct a workshop to get their buy-in into the possible gains with the Three Rules.
4. Create project plans without buffers.14
Define the project’s objective and the task that will signify achievement of that objective. This is the end-task.
Identify tasks whose completion is required immediately preceding the end task.
Identify tasks immediately preceding each of those tasks.
Keep working backward in this fashion until you get to the starting tasks.
From the starting tasks, work forward one-by-one to validate succeeding tasks. This will identify any tasks