respond with one paragraph for each page (3 paragraphs)
Buffer sizing methods
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Project buffers are used to provide cushion for the project and the individual task that make up the project. The buffers provide extra time, so the project can remain on schedule even with minor delays. CCPM uses four different methods for working with buffers. The four methods are 50% of the difference, square off the sum of the squares, bias plus SSQ, Monte Carlo analysis (Leach, 2014). Each method has strengths and weaknesses, but when used properly they can be beneficial to a project.
The first method or 50% of the difference estimates buffers by calculating the difference between low-risk and the average task and dividing that in half. This is a simple method, but sometimes causes buffers to be too large. The second method or square of the sum of the squares also uses the difference between low-risk and the mean, but it uses the square root of the difference squared. This method takes into account unexpected variation, but can create undersized buffer. The third method or bias plus SSQ combine the first two methods. The fourth and final method or Monte Carlo analysis is the most complicated, but encompasses many of the other advantages of the previous method (Leach, 2014).
Each method has its advantages, but I would suggest using method 3, bias plus SSQ. This method provides a simple platform that offers a high level of control over accuracy.
Reference
Leach, L.P. (2014). Critical chain project management. (3rd Ed.). Boston: Artech House
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Less is more...
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Class,
The “less is more” more approach is interesting to me because I have grown up in a military culture where if it is not on paper then it won’t happen or it didn’t happen. Leach did discuss where some project managers are very proud of having very high number of tasks associated with the project because they have “thought of everything”. However, as a project manager you are not as worried with the individual tasks that it takes to complete the work packages and the overarching project as you are with big muscle movements and milestones being accomplished on time and budget. Additionally, as a project manager you have a vast amount of breadth, but typically very little depth in the various specialties that are required to accomplish the project. Therefore, it is not feasible nor necessary for a project plan to identify every single task that will be accomplished. The project manager should allow is section managers/leads run their part of the project the way they see fit because they have a better handle on their resources and what needs to be accomplished. I would suggest that project managers focus on the big moving parts and go to the individual section leads to determine the time, budget, resources, and project flow and use that large scale information as the skeleton for their project plan. Also, when you plan out every single task, if something were to go wrong or a better way of accomplishing the task were to be found you could jeopardize the project and contract. Another thing that having too much granularity to a project does is stifle empowerment. If the worker on the operations floor knows a more effective or efficient way of accomplishing a task, but is restricted to what the project plan says even though the end-state is the same you run the risk of not being as efficient, effective or creating an environment with so much micromanaging that it reduces individual buy-in, which is key to success. I say identify the necessary information and allow your individual personal the latitude to innovate within the project time line and budget.
Let me know your thought because my experiential knowledge is very different from individuals in industry.
-Steven
Reference:
Leach, L. P. (2014). Critical chain project management. (3rd ed.). Boston, MA: Artech House. Inc.
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Todd Johnson - Question #3
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The project manager must not reduce the project buffer in an attempt to accelerate the CCPM schedule. This should not even be a consideration as it will not accelerate the project. Instead, it will only increase the likelihood that you will not meet the deadline and it will increase buffer triggers. According to Leach (2014), "Two primary options are to get additional resources where resolving overloads causes the lead time to be increased and to look inside the tasks for batching opportunities" (p. 191).
Both of these are possible without a negative cost or throughput impact if managed correctly. You must make sure that you do not increase the task work when adding an additional resource as this will have an impact on cost. Batching will require breaking up the task into smaller pieces. If managed correctly, both options will accelerate the schedule.
References
Leach, L. P. (2014). Critical chain project management (3rd ed.). Boston, MA: Artech House.
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