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Troubleshoot scheduling tasks
 

ShowA task in my project starts earlier than the project start date

Cause   You might have set a date constraint (inflexible constraint: A constraint that is inflexible because it ties a task to a date. The inflexible constraints are Must Finish On, Must Start On, Finish No Earlier Than, Finish No Later Than, Start No Earlier Than, and Start No Later Than.), such as Start No Earlier Than (SNET) or Must Start On (MSO), which ties the task to a date earlier than the project's start date. These constraints can cause the task to be scheduled before the project's start date.

ShowSolution

Reset the constraint if the task should begin no earlier than the project's start date. Select the task, click Task Information, and then click the Advanced tab. In the Constraint type box, click As Soon As Possible.

Cause   The task might have an external dependency (external dependency: A relationship in which the start or finish date of a task depends on a task in another project.) to a task in another project. That dependency might be causing the task to start earlier than the project start date.

ShowSolution

If you need to keep this external dependency, change the project start date to match the external dependency date. On the Project menu, click Project Information. In the Start date box, enter the new date.

Cause   The task might have an actual start date recorded before the project start date.

ShowSolution

If the actual start date is wrong, select the task, and then on the Tools menu, point to Tracking, and then click Update Tasks. Under Actual, change the date in the Start box.

ShowA task's duration doesn't match the length of its Gantt bar

Cause   If you have changed the working time (working time: Hours designated in a resource or project calendar during which work can occur.) in the project calendar (project calendar: The base calendar used by a project.) to more or fewer than 8 hours of working time per day, tasks' durations (duration: The total span of active working time that is required to complete a task. This is generally the amount of working time from the start to finish of a task, as defined by the project and resource calendar.) won't match their Gantt bars (Gantt bar: A graphical element on the chart portion of the Gantt Chart view representing the duration of a task.).

ShowSolution

  1. On the Tools menu, click Change Working Time.
  2. In the For box, click Standard (Project Calendar). For all days including those showing edited working hours, note the earliest start and latest finish times in the From and To boxes.
  3. Figure out the total working hours for the day. For example, the default settings are from 8:00 A.M. to 12:00 P.M. and from 1:00 P.M. to 5:00 P.M., for a total of 8 working hours.
  4. Click Cancel to close the Change Working Time dialog box.
  5. On the Tools menu, click Options, and then click the Calendar tab.
  6. In the Hours per day box, type or select the total number of working hours per day from the project calendar. Note that this setting is only used to define how long a day is when entering durations, for example, what is meant when you enter a duration of 3 days.
Tip   You can also use the Project Working Times side pane to quickly set the number of working hours per day in the project calendar. On the Project Guide toolbar, click Tasks, and then click Define general working times. Then follow the instructions that appear in the side pane.

Cause   If you have changed nonworking time (nonworking time: Hours or days designated in a resource or project calendar when Project should not schedule tasks because work is not done. Nonworking time can include lunch breaks, weekends, and holidays, for example.) in the resource calendar (resource calendar: A calendar that specifies working and nonworking time for an individual resource. A resource calendar differs from a base calendar, which specifies working and nonworking time for more than one resource.) of the resource assigned to the task, the task may be scheduled during a resource's nonworking time, so work on the task is suspended until the resource is scheduled to work again. The Gantt bar spans this nonworking time, so it appears longer than the task's duration.

ShowSolution

  1. On the View menu, click Resource Sheet.
  2. Select the resource assigned to the task.
  3. Click Resource Information, and then click the Working Time tab.
  4. In the Base calendar box, click Standard.
  5. During the time the task is scheduled, check the calendar for edited working hours that may affect the total number of hours worked per day. Make sure that the calendar settings are appropriate for the resource.
  6. If there's a mistake in the resource calendar, and you want to reset the resource calendar to the default number of working hours per day, select the date, multiple dates, day of the week, or all working days, and under Set selected date(s) to, click Use default. To select a day of the week, click the abbreviation for the day, such as M to select all Mondays.

Cause   If a task's duration spans nonworking time in the project calendar or in a task calendar (task calendar: The base calendar that you can apply to individual tasks to control their scheduling, usually independent of the project calendar or any assigned resources' calendars. By default, all tasks use the project calendar.) with nonworking time applied to the task, the Gantt bar in the Gantt Chart may appear longer than the task's duration.

ShowSolution

Review the task calendar and make sure it's set the way you need. The working and nonworking times in the task calendar control how the task is scheduled.

  1. Click the task, and then click Task Information.
  2. Click the Advanced tab.
  3. Review the Calendar box to find the name of the task calendar.
  4. Close the Task Information dialog box.
  5. To review or change the working and nonworking time for the task calendar, on the Tools menu, click Change Working Time.
  6. In the For box, select the name of the calendar that you saw is attached to the task.
  7. Review the working times and nonworking times and make sure they are what's required by the task. Make any necessary adjustments.
    • To change one day of the week for the entire calendar (for example, to have work on Fridays end at 4:00 P.M.), click the abbreviation for that day at the top of the calendar.
    • To change all the working days (for example, to have every working day begin at 9:00 A.M.), hold down SHIFT, and then click the abbreviations for the first and last day you want to change.
  8. Click Use default, Nonworking time, or Nondefault working time.

    If you click Nondefault working time, type the times you want work to start in the From boxes and the times you want work to end in the To boxes.

Cause   If the scheduling default time units for days, weeks, and months do not match the values of task, resource, or project calendars, the Gantt bar in the Gantt Chart may appear longer than the task's duration. For example, if you've entered a task with a 1-day duration, but changed the default hours per working day to 16 hours, then the task's duration will appear as .5 days yet its Gantt bar will span a full day.

ShowSolution

  1. On the Tools menu, click Options, and then click the Calendar tab.
  2. To change the default start or end time for scheduled tasks, change the time in the Default start time and Default end time boxes.
  3. If you want to change how many hours Microsoft Office Project 2003 schedules for 1 day, enter it in the Hours per day box.

    For example, if you want Project to schedule 6 hours when you enter a 1-day duration, enter 6 in the Hours per day box.

  4. If you want to change how many hours Project schedules for 1 week, enter it in the Hours per week box.

    For example, if you want Project to schedule 30 hours when you enter a 1-week duration, enter 30 in the Hours per week box.

  5. If you want to change how many days Project schedules for 1 month, enter it in the Days per month box.

    For example, if you want Project to schedule 24 days when you enter a 1-month duration, enter 24 in the Days per month box.

Cause   If Gantt bar rounding to whole days is turned on, the Gantt bar in the Gantt Chart might appear longer than the task's duration. This feature adjusts the Gantt Bars to full days, based on the default start and finish times set in the Options dialog box, Calendar tab.

ShowSolution

Determine whether you want to retain Gantt bar rounding to full days. You can turn off the setting if you find it's more of a hindrance than a help.

  1. On the View menu, click Gantt Chart.
  2. On the Format menu, click Layout.
  3. Clear the Round bars to whole days check box.

ShowA task's start and finish dates change when I adjust the duration

If you enter a task's duration (duration: The total span of active working time that is required to complete a task. This is generally the amount of working time from the start to finish of a task, as defined by the project and resource calendar.), Project calculates when the task should start and finish based on the project's start date and the duration, as well as any nonworking time (nonworking time: Hours or days designated in a resource or project calendar when Project should not schedule tasks because work is not done. Nonworking time can include lunch breaks, weekends, and holidays, for example.), such as weekends. If you later change the task's duration, Project recalculates the dates to correspond to the duration.

For example, if you enter a duration of three days, and the project's start date is March 1, Project calculates the task's start date (start date: The date when a task is scheduled to begin. This date is based on the duration, calendars, and constraints of predecessor and successor tasks. A task's start date is also based on its own calendars and constraints.) as March 1 and the finish date (finish date: The date that a task is scheduled to be completed. This date is based on the task's start date, duration, calendars, predecessor dates, task dependencies, and constraints.) as March 3 (unless those dates happen to fall on a weekend or other nonworking time). If you change the duration to four days, the finish date finish is recalculated to March 4.

ShowSolutions

If you want to enter specific start and finish dates for a task, enter the task's start and finish dates and Project recalculates the duration. Be aware that entering the start and finish dates sets a date constraint (constraint: A restriction set on the start or finish date of a task. You can specify that a task must start on or finish no later than a particular date. Constraints can be flexible [not tied to a specific date] or inflexible [tied to a specific date].) on the task, which limits the flexibility of your schedule (schedule: The timing and sequence of tasks within a project. A schedule consists mainly of tasks, task dependencies, durations, constraints, and time-oriented project information.). If you enter a start date and then enter a finish date, a Finish No Earlier Than (FNET) constraint is set. Or if you enter a finish date and then enter a start date, a Start No Earlier Than (SNET) constraint is set.

If you want a task to start or finish on a certain date but want to retain the flexibility of the schedule while being alerted if a task will not start or finish on time, you can enter a deadline (deadline: A target date indicating when you want a task to be completed. If the deadline date passes and the task is not completed, Project displays an indicator.) date for the task. Deadlines do not constrain tasks nor do they affect constraints. As the schedule is updated, an indicator (indicators: Small icons representing information for a task or resource that are displayed in the Indicators field. The Indicators field is located to the right of the ID field and appears in a number of tables.) appears if a task is pushed beyond its deadline.

ShowA task's duration changes when I change its start and finish dates

Cause   If you enter task start (start date: The date when a task is scheduled to begin. This date is based on the duration, calendars, and constraints of predecessor and successor tasks. A task's start date is also based on its own calendars and constraints.) and finish dates (finish date: The date that a task is scheduled to be completed. This date is based on the task's start date, duration, calendars, predecessor dates, task dependencies, and constraints.) instead of a duration (duration: The total span of active working time that is required to complete a task. This is generally the amount of working time from the start to finish of a task, as defined by the project and resource calendar.), Project calculates the duration based on the working time (working time: Hours designated in a resource or project calendar during which work can occur.) between those dates. If you later change the start or finish dates (but don't change the duration), the duration is recalculated.

Of a task's duration, start date, and finish date fields (field: A location in a sheet, form, or chart that contains a specific kind of information about a task, resource, or assignment. For example, in a sheet, each column is a field. In a form, a field is a named box or a place in a column.), Project tracks the last two fields edited and recalculates the earliest edited of those three fields based on the latest thing you changed. So if you enter a start date and then enter a finish date, the duration is calculated; if you then change the duration, the start date is recalculated.

For example, if you enter a start date of May 1 and a finish date of May 4, Project calculates the duration as three days. If you change the finish date to May 5, the duration is recalculated to four days. But if you change the finish date to May 8 instead of editing the duration, Project recalculates the start date to May 4, keeping the duration constant at four days because the last two fields you changed were for the finish date and duration.

ShowSolution

If you must enter start and finish dates, and if you want the duration to remain constant, make sure the new start and finish dates represent the same number of working days as the previous dates. The duration will remain the same as before.

ShowVariances in my project look wrong

Cause   You might not have saved a baseline (baseline plan: The original project plans [up to 11 per project] used to track progress on a project. The baseline plan is a snapshot of your schedule at the time that you save the baseline and includes information about tasks, resources, and assignments.). The variance (variance: The difference between baseline and scheduled task or resource information, they usually occur when you set a baseline plan and begin entering actual information into your schedule. Variances can occur in work, costs, and schedule.) is the baseline value compared to the actual (actual: Information that shows what has actually occurred. For example, the actual start date for a task is the day that the task actually started.) value for a field (field: A location in a sheet, form, or chart that contains a specific kind of information about a task, resource, or assignment. For example, in a sheet, each column is a field. In a form, a field is a named box or a place in a column.). Without a baseline, Project calculates this difference using a 0 value from the baseline fields. This results in variances that are as large as the scheduled field itself. For example, suppose you have a scheduled cost of $60 for a task. If no baseline is set, the baseline cost is $0. The Cost Variance field therefore shows $60.

ShowSolutions

Save a baseline now. On the Tools menu, point to Tracking, and then click Save Baseline. Even though you have already started your project, the baseline values will be valid for later tasks that have not yet started.

Find a backup of the project as it was just before you started tracking progress. Open that project file, save a baseline, and then enter tracking information to catch you up to date.

Cause   You might have saved multiple baselines, but Microsoft Office Project 2003 uses only the initial baseline values (that is, the values for the Baseline field, and not the values for Baseline1 through Baseline10) when calculating variance. In this case, you might see information in variance fields, but they look outdated and possibly too large.

ShowSolution

Copy the values from the baseline fields into the corresponding Baseline fields. On the Tools menu, point to Tracking, and then click Save Baseline. Click Save interim plan. In the Copy list, click the baseline (for example, Baseline3 or Baseline7) that contains the values you want to copy. In the Into list, click Baseline.

Cause   You might have added new tasks (task: An activity that has a beginning and an end. Project plans are made up of tasks.) to a project, but not to the baseline plan. In this case, you might see variances equal to the scheduled values.

ShowSolution

If you add a task to a project after setting a baseline plan, add the task to the baseline plan as well, so that you can compare the baseline task to actual values later on. Select the new tasks and then on the Tools menu, point to Tracking, and then click Save Baseline. Select Save baseline, and then select Selected tasks.

Cause   You might not have updated actual values for those tasks that are completed or in progress. In this case, variances might be equal to the scheduled values or otherwise larger than you expect.

ShowSolution

Update actuals and review the variances again.

Cause   You might have added new tasks or assigned resources (resources: The people, equipment, and material that are used to complete tasks in a project.) and saved a baseline plan, but the baseline information for the summary task (summary task: A task that is made up of subtasks and summarizes those subtasks. Use outlining to create summary tasks. Project automatically determines summary task information [such as duration and cost] by using information from the subtasks.) has not been updated. In this case, accurate variance values are showing for the individual tasks but not for summary tasks.

ShowSolution

Edit the baseline information for the summary task to include the baseline information of the new tasks or assignments (assignment: A specific resource that is assigned to a particular task.). To do this, select the summary task for which you want to update baseline information. On the Tools menu, point to Tracking, and then click Save Baseline. Select Save baseline, and then select Selected tasks. Under Roll up baselines, click From subtasks into selected summary task(s).

ShowTasks are not rescheduled when I change the project to schedule from a finish date

Cause   When you choose to schedule a project from a finish date, you should examine the effects on any tasks (task: An activity that has a beginning and an end. Project plans are made up of tasks.) already in the project. If you initially scheduled your project from a start date, tasks were created with an As Soon As Possible (ASAP) constraint (constraint: A restriction set on the start or finish date of a task. You can specify that a task must start on or finish no later than a particular date. Constraints can be flexible [not tied to a specific date] or inflexible [tied to a specific date].) by default. When you change your project to schedule from a finish date, all new tasks will be created with an As Late As Possible (ALAP) constraint by default. However, the original tasks still have ASAP constraints that can affect when the tasks are scheduled as you enter actual start (start date: The date when a task is scheduled to begin. This date is based on the duration, calendars, and constraints of predecessor and successor tasks. A task's start date is also based on its own calendars and constraints.) and finish dates (finish date: The date that a task is scheduled to be completed. This date is based on the task's start date, duration, calendars, predecessor dates, task dependencies, and constraints.). This can create unnecessary negative slack (slack: The amount of time that a task can slip before it affects another task or the project's finish date. Free slack is how much a task can slip before it delays another task. Total slack is how much a task can slip before it delays the project.) on tasks if tasks start late.

The amount of slack in your schedule (schedule: The timing and sequence of tasks within a project. A schedule consists mainly of tasks, task dependencies, durations, constraints, and time-oriented project information.) tells you how much you can delay tasks before other tasks or the project finish date is affected. Total slack (total slack: The amount of time that the finish date of a task can be delayed without delaying the finish date of the project.) is the amount of time a task can slip (slippage: The amount of time that a task has been delayed from its original baseline plan. The slippage is the difference between the scheduled start or finish date for a task and the baseline start or finish date.) before it delays the project finish date. When the total slack is negative, the task duration (duration: The total span of active working time that is required to complete a task. This is generally the amount of working time from the start to finish of a task, as defined by the project and resource calendar.) is too long for its successor (successor: A task that cannot start or finish until another task starts or finishes.) to begin on the date required by a constraint.

ShowSolution

Examine the task constraints for all your tasks, and change ASAP to ALAP wherever appropriate.

  1. On the View menu, click Gantt Chart.
  2. Click the field (field: A location in a sheet, form, or chart that contains a specific kind of information about a task, resource, or assignment. For example, in a sheet, each column is a field. In a form, a field is a named box or a place in a column.) to the right of where you want to insert the new field. For example, click the Task Name field to insert the field immediately to the left of the task's name.
  3. On the Insert menu, click Column.
  4. In the Field name box, click Constraint Type, and then click Best Fit.
  5. To identify any tasks that have ASAP constraints and, if appropriate, change them to ALAP constraints, click AutoFilter Button image.
  6. Click the AutoFilter arrow in the Constraint Type field heading, and then click As Soon As Possible.
  7. Click the arrow in the Constraint Type field of the first task displayed, and then click As Late As Possible.
  8. Point to the lower-right corner of the field. When the pointer changes to a plus sign, drag down to set the fields for all the tasks to As Late As Possible.
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