THE STUDENTS SYNDROME AND CRITICAL CHAIN
Student syndrome refers to the phenomenon that many people will start to fully apply themselves to a task just at the last possible moment before a deadline. This leads to wasting any buffers built into individual task duration estimates.
The student syndrome is a form of procrastination, but with more of a plan with good intention. For example, if a student or group of students goes to a professor and asks for an extension to a deadline they will usually defend their request by noting how much better their project will be given more time to work on it; they request this with all the right intentions. In reality most students will have other tasks or events place a demand on the time they fully intended to commit to improving their paper or project. In the end they will often end up close to the same situation they started with wishing they had more time as the new delayed deadline approaches.
This same behaviour is seen in businesses; in project and task estimating, a time- or resource-buffer is applied to the task to allow for overrun or other scheduling problems. However with Student syndrome the latest possible start of tasks in which the buffer for any given task is wasted beforehand, rather than kept in reserve. Like students, many workers do not complete assignments early, but wait until the last minute before starting, often having to rush to submit their assignment minutes before the deadline. A similar phenomenon is seen every year in the United States when personal tax returns are due - Post Offices remain open until midnight on the final day as people queue to get their tax return postmarked.
CRITICAL CHAIN AND ITS CONNECTION-
With traditional project management methods, 30% of the lost time and resources are typically consumed by wasteful techniques such as bad multi-tasking, Student syndrome, In-box delays, and lack of prioritization.
In project management, the critical chain is the sequence of both precedence- and resource-dependent terminal elements that prevents a project from being completed in a shorter time, given finite resources. If resources are always available in unlimited quantities, then a project's critical chain is identical to its critical path.
Critical chain is used as an alternative to critical path analysis. The main features that distinguish the critical chain from the critical path are:
1. The use of (often implicit) resource dependencies. Implicit means that they are not included in the project network but have to be identified by looking at the resource requirements.
2. Lack of search for an optimum solution. This means that a "good enough" solution is enough because:
1. As far as is known, there is no analytical method of finding an absolute optimum (i.e. having the overall shortest critical chain).
2. The inherent uncertainty in estimates is much greater than the difference between the optimum and near-optimum ("good enough" solutions).
3. The identification and insertion of buffers:
* project buffer
* feeding buffers
* resource buffers.
4. Monitoring project progress and health by monitoring the consumption rate of the buffers rather than individual task performance to schedule.
CCPM aggregates the large amounts of safety time added to many subprojects in project buffers to protect due-date performance, and to avoid wasting this safety time through bad multitasking, student syndrome, Parkinson's Law and poorly synchronised integration.
Critical chain project management uses buffer management instead of earned value management to assess the performance of a project. Some project managers feel that the earned value management technique is misleading, because it does not distinguish progress on the project constraint (i.e. on the critical chain) from progress on non-constraints (i.e. on other paths). Event chain methodology can be used to determine a size of project, feeding, and resource buffers.
METHODOLOGY
Planning
A project plan is created in much the same fashion as with critical path. The plan is worked backward from a completion date with each task starting as late as possible. Two durations are entered for each task: a "best guess," or 50% probability duration, and a "safe" duration, which should have higher probability of completion (perhaps 90% or 95%, depending on the amount of risk that the organization can accept).
Resources are then assigned to each task, and the plan is resource leveled using the 50% estimates. The longest sequence of resource-leveled tasks that lead from beginning to end of the project is then identified as the critical chain. The justification for using the 50% estimates is that half of the tasks will finish early and half will finish late, so that the variance over the course of the project should be zero.
Recognizing that tasks are more likely to take more rather than less time due to Parkinson's Law, Student's Syndrome, or other reasons, "buffers" are used to establish dates for deliverables and for monitoring project schedule and financial performance. The "extra" duration of each task on the critical chain—the difference between the "safe" durations and the 50% durations—is gathered together in a buffer at the end of the project. In the same way, buffers are gathered at the end of each sequence of tasks that feed into the critical chain.
Finally, a baseline is established, which enables financial monitoring of the project.
Execution
When the plan is complete and the project ready to kick off, the project network is fixed and the buffers size is "locked" (i.e. their planned duration may not be altered during the project), because they are used to monitor project schedule and financial performance.
With no slack in the duration of individual tasks, the resources on the critical chain are exploited by ensuring that they work on the critical chain task and nothing else; bad multitasking is eliminated. An analogy is drawn in the literature with a relay race. The critical chain is the race, and the resources on the critical chain are the runners. When they are running their "leg" of the project, they should be focused on completing the assigned task as quickly as possible, with no distractions or multitasking. In some case studies, actual batons are reportedly hung by the desks of people when they are working on critical chain tasks so that others know not to interrupt. The goal, here, is to overcome the tendency to delay work or to do extra work when there seems to be time.
Because task durations have been planned at the 50% probability duration, there is pressure on the resources to complete critical chain tasks as quickly as possible, overcoming student's syndrome and Parkinson's Law.
Monitoring
Monitoring is, in some ways, the greatest advantage of the Critical Chain method. Because individual tasks will vary in duration from the 50% estimate, there is no point in trying to force every task to complete "on time;" estimates can never be perfect. Instead, we monitor the buffers that were created during the planning stage. A fever chart or similar graph can be easily created and posted to show the consumption of buffer as a function of project completion. If the rate of buffer consumption is low, the project is on target. If the rate of consumption is such that there is likely to be little or no buffer at the end of the project, then corrective actions or recovery plans must be developed to recover the loss. When the buffer consumption rate exceeds some critical value (roughly: the rate where all of the buffer may be expected to be consumed before the end of the project, resulting in late completion), then those alternative plans need to be implemented.
Theory of Constraints (TOC) is an overall management philosophy that aims to continually achieve more of the goal of a system. If that system is a for-profit business, then the goal is to make more money, both now and in future. TOC consists of two primary collections of work: 1) The five focusing steps and their application to operations; 2) The Thinking Processes and their application to project management and human behavior.
According to TOC, every organization has - at any given point in time - one key constraint which limits the system's performance relative to its goal (see Liebig's Law of the Minimum). These constraints can be broadly classified as either an internal constraint or a market constraint. In order to manage the performance of the system, the constraint must be identified and managed correctly (according to the Five Focusing Steps below). Over time the constraint may change (eg because the previous constraint was managed successfully, or because of a changing environment) and the analysis starts anew.
The student syndrome is a form of procrastination, but with more of a plan with good intention. For example, if a student or group of students goes to a professor and asks for an extension to a deadline they will usually defend their request by noting how much better their project will be given more time to work on it; they request this with all the right intentions. In reality most students will have other tasks or events place a demand on the time they fully intended to commit to improving their paper or project. In the end they will often end up close to the same situation they started with wishing they had more time as the new delayed deadline approaches.
This same behaviour is seen in businesses; in project and task estimating, a time- or resource-buffer is applied to the task to allow for overrun or other scheduling problems. However with Student syndrome the latest possible start of tasks in which the buffer for any given task is wasted beforehand, rather than kept in reserve. Like students, many workers do not complete assignments early, but wait until the last minute before starting, often having to rush to submit their assignment minutes before the deadline. A similar phenomenon is seen every year in the United States when personal tax returns are due - Post Offices remain open until midnight on the final day as people queue to get their tax return postmarked.
CRITICAL CHAIN AND ITS CONNECTION-
With traditional project management methods, 30% of the lost time and resources are typically consumed by wasteful techniques such as bad multi-tasking, Student syndrome, In-box delays, and lack of prioritization.
In project management, the critical chain is the sequence of both precedence- and resource-dependent terminal elements that prevents a project from being completed in a shorter time, given finite resources. If resources are always available in unlimited quantities, then a project's critical chain is identical to its critical path.
Critical chain is used as an alternative to critical path analysis. The main features that distinguish the critical chain from the critical path are:
1. The use of (often implicit) resource dependencies. Implicit means that they are not included in the project network but have to be identified by looking at the resource requirements.
2. Lack of search for an optimum solution. This means that a "good enough" solution is enough because:
1. As far as is known, there is no analytical method of finding an absolute optimum (i.e. having the overall shortest critical chain).
2. The inherent uncertainty in estimates is much greater than the difference between the optimum and near-optimum ("good enough" solutions).
3. The identification and insertion of buffers:
* project buffer
* feeding buffers
* resource buffers.
4. Monitoring project progress and health by monitoring the consumption rate of the buffers rather than individual task performance to schedule.
CCPM aggregates the large amounts of safety time added to many subprojects in project buffers to protect due-date performance, and to avoid wasting this safety time through bad multitasking, student syndrome, Parkinson's Law and poorly synchronised integration.
Critical chain project management uses buffer management instead of earned value management to assess the performance of a project. Some project managers feel that the earned value management technique is misleading, because it does not distinguish progress on the project constraint (i.e. on the critical chain) from progress on non-constraints (i.e. on other paths). Event chain methodology can be used to determine a size of project, feeding, and resource buffers.
METHODOLOGY
Planning
A project plan is created in much the same fashion as with critical path. The plan is worked backward from a completion date with each task starting as late as possible. Two durations are entered for each task: a "best guess," or 50% probability duration, and a "safe" duration, which should have higher probability of completion (perhaps 90% or 95%, depending on the amount of risk that the organization can accept).
Resources are then assigned to each task, and the plan is resource leveled using the 50% estimates. The longest sequence of resource-leveled tasks that lead from beginning to end of the project is then identified as the critical chain. The justification for using the 50% estimates is that half of the tasks will finish early and half will finish late, so that the variance over the course of the project should be zero.
Recognizing that tasks are more likely to take more rather than less time due to Parkinson's Law, Student's Syndrome, or other reasons, "buffers" are used to establish dates for deliverables and for monitoring project schedule and financial performance. The "extra" duration of each task on the critical chain—the difference between the "safe" durations and the 50% durations—is gathered together in a buffer at the end of the project. In the same way, buffers are gathered at the end of each sequence of tasks that feed into the critical chain.
Finally, a baseline is established, which enables financial monitoring of the project.
Execution
When the plan is complete and the project ready to kick off, the project network is fixed and the buffers size is "locked" (i.e. their planned duration may not be altered during the project), because they are used to monitor project schedule and financial performance.
With no slack in the duration of individual tasks, the resources on the critical chain are exploited by ensuring that they work on the critical chain task and nothing else; bad multitasking is eliminated. An analogy is drawn in the literature with a relay race. The critical chain is the race, and the resources on the critical chain are the runners. When they are running their "leg" of the project, they should be focused on completing the assigned task as quickly as possible, with no distractions or multitasking. In some case studies, actual batons are reportedly hung by the desks of people when they are working on critical chain tasks so that others know not to interrupt. The goal, here, is to overcome the tendency to delay work or to do extra work when there seems to be time.
Because task durations have been planned at the 50% probability duration, there is pressure on the resources to complete critical chain tasks as quickly as possible, overcoming student's syndrome and Parkinson's Law.
Monitoring
Monitoring is, in some ways, the greatest advantage of the Critical Chain method. Because individual tasks will vary in duration from the 50% estimate, there is no point in trying to force every task to complete "on time;" estimates can never be perfect. Instead, we monitor the buffers that were created during the planning stage. A fever chart or similar graph can be easily created and posted to show the consumption of buffer as a function of project completion. If the rate of buffer consumption is low, the project is on target. If the rate of consumption is such that there is likely to be little or no buffer at the end of the project, then corrective actions or recovery plans must be developed to recover the loss. When the buffer consumption rate exceeds some critical value (roughly: the rate where all of the buffer may be expected to be consumed before the end of the project, resulting in late completion), then those alternative plans need to be implemented.
Theory of Constraints (TOC) is an overall management philosophy that aims to continually achieve more of the goal of a system. If that system is a for-profit business, then the goal is to make more money, both now and in future. TOC consists of two primary collections of work: 1) The five focusing steps and their application to operations; 2) The Thinking Processes and their application to project management and human behavior.
According to TOC, every organization has - at any given point in time - one key constraint which limits the system's performance relative to its goal (see Liebig's Law of the Minimum). These constraints can be broadly classified as either an internal constraint or a market constraint. In order to manage the performance of the system, the constraint must be identified and managed correctly (according to the Five Focusing Steps below). Over time the constraint may change (eg because the previous constraint was managed successfully, or because of a changing environment) and the analysis starts anew.