Project Rescheduling

Reschedule Project From Start or Finish Date

This topic shows how to reschedule a project from the project start/finish date using Aspose.Tasks for Java.

Rescheduling a Project from the Finish Date

We can recalculate dates from the finish date by setting the project finish date and then invoking the Project.recalculate() method. You can calculate tasks slacks based on their early/late dates.

Programming Sample

The following lines of code show how to achieve this using Java

// For complete examples and data files, please go to https://github.com/aspose-tasks/Aspose.Tasks-for-Java
// The path to the documents directory.
String dataDir = Utils.getDataDir(RescheduleProjectFromStartOrFinishDate.class);

Project project = new Project(dataDir + "Project.mpp");
project.set(Prj.SCHEDULE_FROM_START, new NullableBool(false));
java.util.Calendar cal = java.util.Calendar.getInstance();
cal.set(2020, 1, 1, 0, 0, 0);
project.set(Prj.FINISH_DATE, cal.getTime());

// Now all tasks dates (Start, Finish, EarlyStart, EarlyFinish,
// LateStart,
// LateFinish) are calculated.
// To get the critical path we need to calculate slacks (can be invoked
// in
// separate thread, but only after calculation of all early/late dates)
project.recalculate();
TaskCollection criticalPath = project.getCriticalPath();

Rescheduling a Project from the Start Date

We can calculate dates from start date by setting the project start date and then invoke the Project.recalculate() method.

The following lines of code show how to achieve this using Java.

// For complete examples and data files, please go to https://github.com/aspose-tasks/Aspose.Tasks-for-Java
// The path to the documents directory.
String dataDir = Utils.getDataDir(RescheduleProjectFromStartOrFinishDate.class);

Project project = new Project(dataDir + "Project.mpp");
project.set(Prj.SCHEDULE_FROM_START, new NullableBool(true));
java.util.Calendar cal = java.util.Calendar.getInstance();
cal.set(2020, 1, 1, 0, 0, 0);
project.set(Prj.START_DATE, cal.getTime());

// Now all tasks dates (Start, Finish, EarlyStart, EarlyFinish,
// LateStart,
// LateFinish) are calculated.
// To get the critical path we need to calculate slacks (can be invoked
// in
// separate thread, but only after calculation of all early/late dates)
project.recalculate();
TaskCollection criticalPath = project.getCriticalPath();

Update Project and Reschedule Uncompleted Work

Microsoft Project lets users update and reschedule work through a defined date. This helps identify work completed up to the specified date as well as reschedule any uncompleted work from a specified date. Aspose.Tasks’ Project API provides the same functionality by exposing the updateProjectWorkAsComplete and rescheduleUncompletedWorkToStartAfter methods. This article provides a working example of both these methods as a single use case.

Update Project

This topic demonstrates how to update a project through a specified date. The updateProjectWorkAsComplete method updates all the work as complete through a specified date for an entire project.

• If the Boolean input parameter is set to true, the method updates only those tasks to 100% complete that have finish dates before the specified completed-through date.
• If the Boolean input parameter is set to false, the method calculates a percentage complete value based on the scheduled state and complete through dates.
• If a list of task is specified, the method updates all work as complete through the specified date for the list of tasks.

The following sample demonstrates how to achieve this

// For complete examples and data files, please go to https://github.com/aspose-tasks/Aspose.Tasks-for-Java
// The path to the documents directory.
String dataDir = Utils.getDataDir(UpdateProjectAndRescheduleuncompletedwork.class);

long OneSec = 10000000;// microsecond * 10
long OneMin = 60 * OneSec;
long OneHour = 60 * OneMin;

Project project = new Project();

java.util.Calendar cal = java.util.Calendar.getInstance();
cal.set(2014, 1, 27, 8, 0, 0);
project.set(Prj.START_DATE, cal.getTime());

Task task1 = project.getRootTask().getChildren().add("Task 1");
Task task2 = project.getRootTask().getChildren().add("Task 2");
task2.set(Tsk.DURATION, task2.getParentProject().getDuration(16, TimeUnitType.Hour));
Task task3 = project.getRootTask().getChildren().add("Task 3");
task3.set(Tsk.DURATION, task2.getParentProject().getDuration(24, TimeUnitType.Hour));
Task task4 = project.getRootTask().getChildren().add("Task 4");
task4.set(Tsk.DURATION, task2.getParentProject().getDuration(16, TimeUnitType.Hour));
Task task5 = project.getRootTask().getChildren().add("Task 5");
task5.set(Tsk.DURATION, task2.getParentProject().getDuration(16, TimeUnitType.Hour));

TaskLink link12 = project.getTaskLinks().add(task1, task2, TaskLinkType.FinishToStart);
TaskLink link23 = project.getTaskLinks().add(task2, task3, TaskLinkType.FinishToStart);
link23.setLinkLag(4800); // one day lag
TaskLink link34 = project.getTaskLinks().add(task3, task4, TaskLinkType.FinishToStart);
TaskLink link45 = project.getTaskLinks().add(task4, task5, TaskLinkType.FinishToStart);

Task task6 = project.getRootTask().getChildren().add("Task 6");
Task task7 = project.getRootTask().getChildren().add("Task 7");
task7.set(Tsk.DURATION, task7.getParentProject().getDuration(24, TimeUnitType.Hour));
Task task8 = project.getRootTask().getChildren().add("Task 8");
task8.set(Tsk.DURATION, task2.getParentProject().getDuration(16, TimeUnitType.Hour));
Task task9 = project.getRootTask().getChildren().add("Task 9");
task9.set(Tsk.DURATION, task2.getParentProject().getDuration(16, TimeUnitType.Hour));
Task task10 = project.getRootTask().getChildren().add("Task 10");

TaskLink link67 = project.getTaskLinks().add(task6, task7, TaskLinkType.FinishToStart);
TaskLink link78 = project.getTaskLinks().add(task7, task8, TaskLinkType.FinishToStart);
TaskLink link89 = project.getTaskLinks().add(task8, task9, TaskLinkType.FinishToStart);
TaskLink link910 = project.getTaskLinks().add(task9, task10, TaskLinkType.FinishToStart);

task6.set(Tsk.IS_MANUAL, new NullableBool(true));
task7.set(Tsk.IS_MANUAL, new NullableBool(true));
task8.set(Tsk.IS_MANUAL, new NullableBool(true));
task9.set(Tsk.IS_MANUAL, new NullableBool(true));
task10.set(Tsk.IS_MANUAL, new NullableBool(true));

project.save(dataDir + "not updated.xml", SaveFileFormat.XML);

cal.set(2014, 1, 28, 17, 0, 0);
project.updateProjectWorkAsComplete(cal.getTime(), false);

project.save(dataDir + "updated.xml", SaveFileFormat.XML);

cal.set(2014, 1, 28, 17, 0, 0);
project.rescheduleUncompletedWorkToStartAfter(cal.getTime());

project.save(dataDir + "rescheduled.xml", SaveFileFormat.XML);