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Chapter 11 - Shortening Your Schedule Introduction Critical Tasks: The Tasks That Make a Difference Identify Tasks on the Critical Path Sort Critical Tasks by Duration Determine the True Length of a Schedule with Slipped Tasks and Inflexible Constraints Strategies for Cutting the Project Scope Delete Critical Tasks Cut the Scope of a Task Strategies for Reducing Task Duration Assign More Resources Increase Working Hours Assign Overtime Work Strategies for Starting Tasks Earlier Change the Task Sequence Break a Large Task into Smaller Tasks Add Lead Time to Tasks Change the Link Type Change the Constraint Type Change the Task Type Fixed-Units Tasks Fixed-Work Tasks Fixed-Duration Tasks Microsoft Project 98 – Chapter 11 Page of 13 Introduction In many projects, time is the main constraining factor: the project deadline must be met That may mean you need to finish a project sooner than the end date on your project schedule If you’re hemmed in by time limitations, your best solution is to shorten your schedule You can shorten your schedule in three major ways: • Reduce the duration of individual tasks • Cut the project scope, which means removing tasks • Reschedule tasks to start earlier than originally scheduled You can use any or all of these methods to shorten your schedule By combining all three methods, you can make the biggest impact on your schedule Depending on your particular circumstances, you might be restricted to using only one or two For instance, you might not be able to cut the project scope Critical Tasks: The Tasks That Make a Difference When you want to shorten your project schedule, where you begin? You begin by examining your project’s critical tasks, the tasks that must finish on time for the entire project to finish on time The project plan’s critical path is the sequence of tasks that ends on the latest finish date The finish date of the last task in the critical path is the project finish date Microsoft Project 98 – Chapter 11 Page of 13 By default, a critical task has zero total slack time, which is the amount of time a task can slip before it delays the project finish date If any critical task slips, the project finish date will likely slip as well Critical tasks are like stacked sections of a column holding up a roof The column is the critical path, and the roof represents the project finish date Noncritical tasks are like decorative columns that are lower than the roof To raise or lower the roof, you adjust the height of the "critical" column If you increase the height of a column of noncritical tasks so that the roof rests on it instead, then that column becomes "critical." The original column of critical tasks becomes "noncritical." Microsoft Project 98 – Chapter 11 Page of 13 Microsoft Project recalculates the critical path every time you change task data A critical task may become noncritical and a noncritical task may become critical as you assign resources, change links, and so on Decreasing the duration of a You can experiment with your project plan by altering one critical task at a noncritical task has no effect on time Change one element of a critical task to see how the change affects the the project end date schedule as a whole For example, you can reduce a task’s duration to see if that change causes the project to end sooner Or, if a resource assigned to work on two concurrent tasks becomes overworked, you can reschedule one of those tasks But don’t start altering critical tasks to fine-tune your schedule until you can distinguish critical tasks from noncritical ones Microsoft Project provides several ways for you to display critical tasks and focus on the ones to which you should give the most attention Identify Tasks on the Critical Path Because critical tasks play such a key role in determining the project length and finish date, Microsoft Project provides two views that visually distinguish critical tasks from noncritical tasks To enable you to zero in on critical tasks, both the Detail Gantt view and the Tracking Gantt view display critical tasks in red To identify tasks on the critical path On the View Bar, click More Views In the Views list, click Detail Gantt or Tracking Gantt, and then click Apply When you display both critical tasks and noncritical tasks, you can see how altering critical tasks affects both the project end date and noncritical task dates If a noncritical task becomes critical, you may need to alter it to modify its effect on the project end date Sort Critical Tasks by Duration Because critical tasks are the ones that affect project length, the longest critical tasks have the biggest effect When it’s important to maintain or shorten the project length, you’ll want to focus first on shortening the critical tasks with the longest duration You can this most easily by sorting critical tasks by duration To sort critical tasks by duration On the View Bar, click Gantt Chart On the Project menu, point to Filtered for, and then click Critical On the Project menu, point to Sort, and then click Sort by In the Sort by box, click Duration, and then click Descending Click Sort Determine the True Length of a Schedule with Slipped Tasks and Inflexible Constraints Microsoft Project 98 – Chapter 11 Page of 13 As you track progress by entering actual start and finish dates for tasks, you may find that the project finish date remains the same, even when a number of tasks have been completed later or have taken longer than originally planned The reason could be that one or more tasks in your schedule have an inflexible constraint (Must Start On, Must Finish On, Start No Later Than, Finish No Later Than) applied A task with an inflexible constraint doesn’t move, even if predecessor tasks finish later than planned A task with a Must Start On constraint, for example, doesn’t get "pushed" to a later start date if tasks that precede it finish later than their original finish dates Instead, it remains firmly anchored to its specified start date while predecessor tasks move The tasks that follow the inflexible task remain unaffected by the late-starting tasks Therefore, even though tasks that precede the inflexible task are late, and the project as a whole is late, Microsoft Project may show your schedule incorrectly on the original project finish date Because of the task with the Must Start On constraint, Microsoft Project can’t recalculate a more realistic project finish date What you if you want to know the "real" project finish date? You can allow the inflexible task to move without removing its Must Start On constraint You can choose to make schedule changes override constraints By default, Microsoft Project honors constraint dates The start and finish dates of a linked task with an inflexible constraint, such as Must Start On, stay the same even if the schedule changes If you want Microsoft Project to automatically recalculate a constrained task’s start and finish dates when the schedule changes, you can choose to have schedule changes override constraint dates Because tasks with flexible constraints such as As Soon As Possible and As Late As Possible have no fixed dates to honor, they behave the same way regardless of the option you choose When you use constraints in your project plan, you can choose to have schedule changes override constraints or have constraints override schedule changes — for all affected tasks A project plan cannot accommodate both options at the same time To set constraints so schedule changes can override them On the Tools menu, click Options Click the Schedule tab Clear the Tasks will always honor their constraint dates check box Strategies for Cutting the Project Scope No change can affect your project as much as cutting its scope, an action that produces a cascade of benefits In one stroke, you can shorten the project duration, reduce the number of required resources, and slash costs The most obvious way to cut the scope is to remove critical tasks For example, if a software developer can’t complete all the planned features of a new software program by the deadline, he or she can cut some of the Microsoft Project 98 – Chapter 11 Page of 13 features, and thus the tasks required to implement those features This can also be the most difficult method, because you must first identify the tasks that are not absolutely necessary for completing the project Another way to cut the project scope is to reduce the scope of individual tasks A task’s scope consists of the specific task goal and the amount of time and effort required to achieve it By reducing a task’s scope, you may reduce the overall time, effort, and cost required to complete your project Delete Critical Tasks You can delete critical tasks that aren’t absolutely required to meet your project goals When you delete critical tasks, you will probably see an immediate effect: the project ends earlier In addition, you may free up resources that you can assign to more urgent tasks in your project or to other projects When you delete a task that is linked to both its predecessor and successor tasks with finish-to-start (FS) links, Microsoft Project automatically links its predecessor task to its successor task with an FS link (by default) If you delete a task with any other type of link, you need to link its predecessor to its successor manually after you delete the task To delete a critical task On the View Bar, click Gantt Chart In the Task Name field, select the task you want to delete On the Edit menu, click Delete Task Cut the Scope of a Task As you examine your schedule, you may find that some critical tasks accomplish more than they need to, and therefore take longer than necessary For example, if hanging clocks for an exhibit is a critical task, you can reduce its scope by hanging fewer clocks than originally planned When you decide to cut a task’s scope, you show this in your project plan by decreasing the task’s duration Shortening the duration of a critical task can shorten the project duration To decrease the duration of a task On the View Bar, click Gantt Chart On the View menu, point to Table, and then click Entry In the Duration field, enter a new duration for the task Click or press ENTER Strategies for Reducing Task Duration Microsoft Project 98 – Chapter 11 Page of 13 No matter how many times you look through your project plan for ways to cut the scope and eliminate tasks, sometimes you can’t find any You may conclude that all of your project goals are essential and every task in your plan is needed to meet those goals But that conclusion doesn’t help you what you must — shorten the schedule When you’ve determined that the scope is just right and you can’t eliminate Sort tasks by duration to see any more tasks, you can shorten the schedule by reducing the durations of which critical tasks to shorten critical tasks Use the following methods to reduce the durations of critical first tasks: • Assign more resources to tasks Use this method if you have extra resources or underused resources • Increase the working hours for one or more resources Use this method if you can increase the working hours for the resources • Assign overtime work Use this method if resources with the required skills are already fully utilized during their normal working hours and if the budget permits the increased cost Assign More Resources If extra or underused resources are available, you can keep cost increases to a minimum while reducing task duration By assigning additional resources who have available hours during their normal working days, you can pay them at their standard rates, which is less costly than paying overtime to already assigned resources You may already have part-time resources on your team, or you may be able to shift some resources from noncritical tasks to critical tasks You could also hire new resources If additional units of the same resource are available, you can increase the number of resource units assigned to a task For example, if the three painters assigned to paint a wall can’t finish the job soon enough and a fourth painter is available, you can assign the fourth painter to the task For information about resource units, see Chapter 8, "Assigning Resources to Tasks." To assign more resources to a task On the View Bar, click Gantt Chart In the Task Name field, select the task for which you want to assign more resources Click Assign Resources In the Name field, select the resource you want to assign to the task o To assign a single resource, enter a number in the Units field to indicate the percentage of working time you want the resource to spend on the task To assign the resource full-time, enter 100%; for part- time, enter a smaller percentage o To assign several different resources, hold down CTRL, and then select the resources o To assign more than one resource from the same set of resources, enter the number of units in the Units field For example, if you assign two painters from the Painters set, enter 200% Microsoft Project 98 – Chapter 11 Page of 13 If necessary, type the name of a new resource in the Name field Click Assign A check mark to the left of the Name field indicates that the resource is assigned to the selected task To increase the resource units assigned to a task On the View Bar, click Gantt Chart In the Task Name field, select the task for which you want to increase resource units Click Assign Resources In the Units field for the resource, enter the number of resource units you want, and then click Assign Increase Working Hours Sometimes you just can’t get additional resources for the tasks you want to shorten One way to handle this situation is to reduce the durations of those tasks by increasing the number of working hours for the resources already assigned Increase the number of available hours for a resource by increasing the resource’s working hours on his or her resource calendar Microsoft Project calculates a task’s duration based in part on the working hours of assigned resources For example, a painter with a 6-hour working day is assigned full-time to paint gallery walls, a task that requires 12 hours The current task duration is days By increasing the painter’s working day to hours and keeping the painter assigned full-time to the task, the task shrinks to 1.5 days Increase the working hours for a resource only if you want the resource to work longer hours on all assigned tasks within a given period To increase a resource’s work schedule On the Tools menu, click Change Working Time In the For box, click the resource whose calendar you want to change On the calendar, select the days you want to change To change a day of the week for the entire calendar, select the day at the top of the calendar Click Use default or Working time To change working time hours, type the new times in the From and To boxes Assign Overtime Work You might at times be faced with a very constrained situation For example, you won’t be getting additional resources and all your available resources are fully occupied with task assignments each hour of their normal working day To use resources to decrease task durations, there’s only one thing left to do: assign overtime work For each hour of overtime worked, Microsoft Project calculates costs based on the overtime rate you specified for that resource (unless you indicate otherwise) Assigning overtime work can be costly, but sometimes it’s your most efficient option To assign overtime work to a task On the View Bar, click Gantt Chart On the Window menu, click Split Click anywhere in the bottom pane On the Format menu, point to Details, and then click Resource Work In the top pane, select the task for which you want to assign overtime work in the Task Name field In the bottom pane, type the number of hours in the Ovt Work field for each resource Strategies for Starting Tasks Earlier Microsoft Project 98 – Chapter 11 Page of 13 While cutting the project scope and reducing task durations can help you shorten your schedule considerably, you can tighten it further by making critical tasks start earlier than their original start dates When you can’t cut the scope, and reducing task durations isn’t possible or doesn’t shrink your schedule as much as you want, having tasks start earlier might be your only option Depending on your particular situation, you can use some or all of the following methods to have tasks start earlier: • Rearrange tasks in a more efficient order • Break a large task into smaller tasks • Add lead time to tasks • Change the link type • Change the constraint type • Change the task type Change the Task Sequence The sequence in which tasks occur can affect the project duration For example, in preparation for a clockwork exhibit, the tasks "Painting the walls," "Hanging clocks," and "Arranging furniture" are scheduled for Monday, Tuesday, and Wednesday, respectively But, because the walls take 24 hours to dry, clock hanging can’t begin until Wednesday and furniture arranging is pushed to Thursday, causing the schedule to slip However, by switching furniture arranging (which doesn’t depend on the walls being dry) to Tuesday and hanging clocks to Wednesday, the project stays on schedule, without wasting days or possibly increasing the project duration It’s a good idea to check your schedule for instances where it’s more efficient to put tasks in a different order When you find those instances, you can change the task sequence by moving tasks To move a task On the View Bar, click Gantt Chart Click the ID number (usually in the leftmost field of a task row) of the task you want to move The entire row should appear highlighted Click Cut Task Click the ID number of the row where you want to insert the task Click Paste Examine the links between the moved task and its predecessor and successor tasks, changing these links as necessary Break a Large Task into Smaller Tasks Not all critical tasks are necessarily created equal Most of the ones in your schedule probably correspond to a concrete, narrowly defined set of actions But some might actually correspond to several smaller but still significant tasks, each of which should be included in your project plan as a separate task, and which you can Microsoft Project 98 – Chapter 11 Page of 13 then schedule more flexibly than one large task If that’s the case, you can break down these overly large tasks into smaller subtasks Some of the subtasks may not need to be completed in sequence for the work to progress, so you may be able to shorten the critical path by making some of the subtasks noncritical Even if some of the subtasks are critical, you might be able to overlap them or change the link type Smaller, overlapping subtasks can have a shorter total duration than the original longer task Typically, when you use Microsoft Project to break a large task into smaller tasks, you make the large task a summary task by adding subtasks To break a large task into a summary task and subtasks On the View Bar, click More Views In the Views list, click Detail Gantt or Tracking Gantt, and then click Apply In the Task Name field, select a single task on the critical path that could be completed in several steps Click Unlink Tasks Remove the resources assigned to this task For information about removing resources from a task, see Chapter 8, "Assigning Resources to Tasks." Select the task beneath the task you want to change, and then click New Task on the Insert menu Repeat step for each subtask you want to add For each new task, type a name in the Task Name field and a duration in the Duration field In the Task Name field, select all the new tasks, and then click Indent original task The original task becomes a summary task 10 Link the new tasks as appropriate to make them subtasks of the Add Lead Time to Tasks Most likely, you’ve linked many of your tasks with a finish-to-start (FS) link, so that the successor task doesn’t start until its predecessor task finishes In some cases, that dependency might be absolutely necessary and true to life A clock can’t be before it’s built But sometimes the work on a successor task can begin before its predecessor task is entirely finished The work can overlap If the museum crew prepares one gallery wall at a time, maybe they can start hanging clocks before all the walls are finished Microsoft Project 98 – Chapter 11 Page 10 of 13 The way to make FS-linked tasks overlap is to add lead time to the link By adding lead time, you cause the successor task to begin on an earlier date If the successor task is a critical task, adding lead time allows the project to end on an earlier date You might find that you can overlap tasks so much that they start at the same time If that’s the case, you should consider changing the FS link to a start-to-start (SS) link, instead of adding lead time To add lead time On the View Bar, click Gantt Chart In the Task Name field, select the successor task you want, and then click Task Information Click the Predecessors tab In the Lag field, type the lead time you want, as a duration (type a negative number) or as a percentage of the predecessor task duration (type the negative completion percentage) For example, if the predecessor task has a duration of days and you want the successor task to begin day before the predecessor task is completed, type –50% in the Lag field Lead time units are minute, hour, day, and week To specify elapsed duration, precede the time unit with the letter "e" (for example, edays for elapsed days) Elapsed days include weekends and other nonworking days Change the Link Type Tasks linked with a finish-to-start (FS) link add more time to a project’s duration than tasks linked either with start-to-start (SS) or finish-to-finish (FF) links These latter two types of links automatically overlap tasks, which tends to decrease the overall project duration An effective way, then, to decrease the project duration is to look for instances where you can replace FS links with either SS or FF links For example, if two tasks can be started at the same time, you can change the task dependency to an SS link If two tasks can finish at the same time, you can switch to an FF link To check and change a task link On the View Bar, click Gantt Chart Double-click the link line you want to view or change In the Type box, click the task link you want Change the Constraint Type Using constraints, you can control the start or finish date of important tasks Microsoft Project automatically assigns the As Soon As Possible constraint when you enter a task You should set other constraints only when necessary, such as when a client or contract requires that a task begin or end by a specific date Task constraints can help you create a more accurate schedule using detailed information But constraints can also limit your schedule’s flexibility If there’s a scheduling conflict between a constraint and a task dependency, Microsoft Project may schedule the task according to the constraint At various stages in your project, you may want to check the constraints on tasks in your schedule, particularly the tasks on the critical path, to make sure they remain necessary Any constraint that requires you to enter a date should be applied carefully Microsoft Project may recalculate the start and finish dates of a task with a flexible constraint, such as the Start No Earlier Than constraint But fixed-date constraints, such as the Must Start On constraint, prevent Microsoft Project from recalculating the start and finish dates if the schedule changes Fixed-date constraints also limit your ability to level overallocated resources For more information about why you should use constraints cautiously, see Chapter 6, "Tying Tasks to Specific Dates." To examine constraints on tasks On the View Bar, click Gantt Chart On the View menu, point to Table, and then click More Tables In the Tables list, click Constraint Dates, and then click Apply Scroll to the right to view the Constraint Type and Constraint Date fields If a task must start or finish in relation to a specific date, you can change its constraint from the default (As Soon As Possible) or change it back to As Soon As Possible Microsoft Project 98 – Chapter 11 Page 11 of 13 To change a constraint On the View Bar, click Gantt Chart In the Task Name field, select the task for which you want to change the constraint, and then click Task Information Click the Advanced tab, and then click a constraint in the Type box If the constraint requires a date, enter a constraint date in the Date box If you don’t enter a date, Microsoft Project uses the current date as the constraint date Microsoft Project recalculates the start and finish dates of all tasks affected by the change Change the Task Type Microsoft Project considers many factors when setting a task’s start and finish dates (such as contraints you’ve set on the dates, dependencies on other tasks, and the task’s duration) Task duration is crucial Your project’s finish date is determined by the latest finish dates of its tasks Those finish dates are affected by how long the tasks take to complete The duration of each task is determined by resource availability and, most important, by the formula Duration = Work ÷ Resources If you assign resources, Microsoft Project uses this formula as the basis for all its scheduling By default, Microsoft Project calculates duration for you In most cases, you’ll want to use Microsoft Project’s default settings However, if you need to, you can choose which piece of the scheduling equation Microsoft Project calculates by setting the task type: fixed duration, fixed units, or fixed work By default, units are fixed, causing Microsoft Project to calculate duration A task type is a method Microsoft Project uses to calculate the work, duration, and resource units for a task You can choose the method you want Microsoft Project to use on a task-by-task basis The three task types are fixed units, fixed work, and fixed duration Fixed-Units Tasks Units determine the allocation of a resource to a task At 100 percent units, a resource is working full-time; at 50 percent units, the resource is working half-time; and so on By default, units are fixed, meaning allocation remains at the unit value you set As you change resource assignments, Microsoft Project adjusts the duration For example, say you assign two full-time painters to paint the walls in days If you then assign two more fulltime painters, Microsoft Project reduces the duration to days If you adjust the work for individual resources, Microsoft Project recalculates the total work for the task Fixed-Work Tasks When you set a task to fixed work, Microsoft Project does not calculate the work for the tasks or resources Instead, as you change resource assignments, Microsoft Project calculates duration For example, if you assign two painters full-time to paint the walls in days, and then you assign two more fulltime painters to the task, Microsoft Project reduces the duration to days If you adjust the task’s duration, Microsoft Project adjusts each resource’s units For example, if you now increase the duration from days to days, Microsoft Project sets each resource’s units to 50 percent, so each painter works only half-time Fixed-Duration Tasks When duration is fixed, it remains at whatever value you enter and Microsoft Project calculates resource units as you change assignments For example, say you assign two painters full-time to paint the walls in days Later, you assign two more full-time painters Microsoft Project set the units for each painter to 50 percent, because four painters need to work only half-time to complete the walls in days If you adjust the task’s duration, Microsoft Project calculates work In the painting example, the total work for the task is 64 hours (four painters × days × hours per day) If you change the task’s duration to days, Microsoft Project recalculates the total work: four painters working half-time for days is 32 hours To change a task type On the View Bar, click Gantt Chart In the Task Name field, select the task for which you want to change the task type Click the Advanced tab, and then click a task type in the Task type box Microsoft Project 98 – Chapter 11 Page 12 of 13 Microsoft Project 98 – Chapter 11 Page 13 of 13