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having to use plants and equipment to the max. ● In some organizations the most careful and comprehensive project budgets end up being slashed by some senior managers or executives who are operating based on some agenda to which you are not privy. In his book The New Project Management, author J.D. Frame says, "Political meddling in cost and schedule estimating is an everyday occurrence in some organizations." The best antidote against such meddling, says the author, is "the establishment of objective, clearly defined procedures for project selection …" which should be set up so that no one, "no matter how powerful, can unilaterally impose their will on the selection process." The issues raised in this lesson point to the ever present need for project managers to build an appropriate degree of slack into their estimates. This is not to say that you are being dishonest or disloyal to your organization, but rather acknowledging the ruthless rules of project management reality—you hardly ever get the funds you need, and even then, stuff happens! The 30-Second Recap ● Because of irrational exuberance, too often the monetary resources allocated to a project (perhaps even before you stepped aboard) have been underestimated. ● In most organizations, no matter how much you ask for, you can count on not getting it all. ● Perhaps the most effective approach to budgeting combines the top-down and bottom-up techniques. ● Build an appropriate degree of slack into your estimates! Lesson 7. Gantt Charts In this lesson, you learn what a Gantt chart is, why it is so useful in project management, variations you can devise, and how to use Gantt charts to keep your project on schedule. Chart Your Progress Henry L. Gantt, for whom the Gantt chart is named, was employed at the Aberdeen Proving Grounds (part of what is now the U.S. Department of Defense—then called the War Department) in Aberdeen, Maryland—as an ordinance engineer during the First World War. Although nearly a century has passed, the Gantt chart remains widely recognized as a fundamental, highly applicable tool for project managers everywhere. A Gantt chart enables you to view start and stop times easily for project tasks and subtasks. TIP Gantt charts are derived from your work breakdown structure (WBS). If you use an outline for your WBS, the Gantt depicts each of the tasks and subtasks in chronological order. For tasks that begin at the same time and run concurrently, the Gantt chart is a highly convenient tool. However, over-lapping tasks and subtasks can easily be depicted on the Gantt chart as well. A WBS is created from tree diagrams, which also lend themselves to depiction on a Gantt chart—although the process is a bit tricky when it comes to determining overall project sequence and start and stop times. (More on converting tree diagrams to critical path analysis in Lesson 8, "PERT/CPM Charts." ) Two basic forms of Gantt charts are depicted here. The following chart uses bars extending from left to right along the horizontal axis to denote starting and ending times for events or activities. Greater detail could be added if you wish to add subtasks. Color-coding allows you to pinpoint which project workers are handling which tasks and subtasks. The chart shown in the following figure offers a simple plan for depicting the planned sequence of events versus the actual (the shaded bars). It is a rare project indeed where the brunt of the planned events or tasks are closely mirrored by the actual performance and completion of them: A Gantt chart with bars. The chart shown in the next figure is merely an alternative to the previous one. Rather than using bars to depict start and stop times and shaded bars to depict actual performance versus planned performance, this chart uses ● Unshaded triangles pointing up to depict plan start time ● Unshaded triangles pointing down to depict plan end time ● Shaded triangles pointing up to depict actual start time ● Shaded triangles pointing down to depict actual completion time A Gantt chart with triangles. One of the advantages of preparing a Gantt chart in this format is that tasks and subtasks, and planned versus actual timeframes can be depicted on a single line emanating from the left of the chart, extending out along the horizontal axis to the right. The two variations of the Gantt chart depicted above (there are many others), offer a snapshot of a project's progress based on timeframes. In the first figure, although Task 1 didn't start on time, its duration was roughly equal to the original planned time. In Task 2, however, the start time was not only delayed, but the actual completion time for the task was far greater than originally planned. This could signal potential budgetary problems or human resource bottlenecks here or at other points as the project progresses. If the start of Task 3 is not dependent upon the results of Task 2, then the manager can make a decision to initiate Task 3 as scheduled or even earlier, since delays in starting Task 2 may indicate the availability of idle resources. If Task 3, however, is dependent upon the completion of Task 2, or at least the brunt of it, then the project manager may have no alternative but to have Task 3 start late as well. You can see that the delays in Task 1 and Task 2 may have a cascading effect which puts all project activities behind schedule unless the project manager is able to reallocate resources so as to pick up the slack where possible. Variations on a Theme The Gantt chart in the following figure for a construction project depicts an eight-week period that includes four events, three of which are actual tasks and one representing completion of the project. Each of the three tasks has between four and six subtasks. Virtually all project activity is dependent upon maintaining the sequence of events as depicted. The coding at the bottom of the chart indicates critical and noncritical progress related and management critical events. ● Scheduled start and stop times for the duration of tasks are earmarked by solid, downwardpointing triangles emanating from the start and end of progress bars. ● Milestones are depicted by dark diamonds. ● More detail could be added to this chart in the form of other kinds of lines and symbols. The project manager for this chart probably found this level of coding to be useful and convenient for his purposes. TIP Each of the three Gantt charts depicted thus far represent plainly evident ways of illustrating overall project status while including the status of each task. Thus, they serve as valuable tools for keeping project team members abreast of activities, as well as the authorizing party, committees, top managers and executives, and other stakeholders. A Gantt chart for sequential construction. Embellishments Offer Detail The more tasks involved in your project and the more important the sequence between tasks, the greater your propensity to embellish your Gantt chart. The chart in the next figure contains some highly useful added columns. A Gantt chart with multiple predecessors. ● Column 3,"duration," lists how many days each task is scheduled to take. ● Column 4, "predecessors," identifies what needs to be completed before this task can be initiated. Often the previous task needs to be completed, but this isn't always the case: ● For the purchasing Task 7, both Tasks 5 and 6 need to be complete. ● For Tasks 8, 9, and 10, only Task 7 needs to be complete, as Tasks 8, 9, and 10 all start at the same time. ● For Task 12, "install software," Task 10 needs to be complete, but Task 11, which is scheduled to start after, does not. You may wonder, "Why not switch Tasks 11 and 12 in the Gantt chart?" The answer is that Task 11, "developed training," follows directly from the completion of Task 8, "manuals"—whereas Task 12, "install software," directly follows from the completion of Task 10, "set up server." They are listed in sequence on the Gantt chart based on what they follow, not based on when they start. One of the benefits of listing the task duration in days is that it also gives you a strong indicator of required levels of staff support. In the simplest example, if all staff members have the same capability, and a ten-day project requires one staff person per day, you could simply add the total number of days in the duration column and get a total number of staff days necessary for the project. CAUTION Leave yourself (as project manager) out of the duration computation, because you are fully involved in management and not engaged in any individual task. The challenge gets more complex when two, three, four, or more staff people are needed per task for each day of a task's duration or, when varying numbers of staff people are needed per task, per day. It gets complicated further if the skill levels of project staff vary widely. TIP Project management software solves many issues related to multiple resource complexity. First, however, you have to understand the basics with paper and pencil, just as you have to learn the fundamentals of math on your own before being able to successfully use a calculator. Getting a Project Back on Track Whenever you find yourself falling behind in one area, you have to make managerial decisions as to how you will compensate to keep the overall project on track. This involves a shuffling of resources, altering the scope of selected tasks or subtasks, or changing sequence of tasks. Let's visit each of these. ● Reallocating Resources It happens to the best of project managers. You launch into a task, and soon enough you find yourself under-resourced. You didn't know that a particular task or subtask was going to be so challenging. If it's critical to the overall project, it makes sense to borrow resources from other task areas. ● Reducing the Level of Effort on Tasks or Subtasks Just as you discovered that some tasks clearly mandate greater staff resources, you may also find tasks and subtasks that could be completed with less effort than you originally budgeted. Perhaps some subtasks can be combined, or skipped all together. For example, if you're doing survey work, perhaps you can get a reasonable result with eight questions instead of 10. Perhaps you can reduce the total number of interviews by 10 percent. ● Altering the Task Sequence Another possibility when faced with roadblocks is to change the sequence of tasks or subtasks. Can you substitute easier tasks for more challenging ones until some of your other staff resources are free? Perhaps you can devise a sequence that enables some of your more experienced staff members to manage multiple tasks for a brief duration. Thinking Ahead The Gantt chart is a useful device for engaging in "what-if" questions. As you look at the sequence of events, their duration, and the number of allotted staff days, sometimes you see opportunities to make shifts in advance of the need. Such shifts may help things to run more smoothly down the road. TIP If you find that the first several tasks or subtasks to your project are already falling behind, a Gantt chart can help you identify where else this may happen given your operating experience. Hence, you can begin crafting alternative scenarios—alternative Gantt charts that may prove to be more effective for managing the duration of the project. You may have the pleasant experience of having tasks and subtasks completed in far less time than you had originally plotted. So, use the Gantt chart to reschedule subsequent events, moving them up and taking advantage of the temporary gains that have already been realized. In summary, the ease of preparation, use, alteration, and sheer versatility of Gantt charts makes them a marvelous tool for both managing your project and depicting your progress to others. The 30-Second Recap ● The Gantt chart is widely recognized as a fundamental, highly applicable tool for project managers to enable one to easily view start and stop times for project tasks and subtasks. ● The more tasks involved in your project and the more important the sequence between tasks, the greater your propensity and desire to embellish your Gantt chart. ● The Gantt chart helps answer "what-if" questions when you see opportunities to make shifts in advance of the need.