Create schedule

Once your tasks and resources have been defined, they can be used to generate a new schedule. The schedule includes the start and end times for each task that was successfully scheduled and a list of any tasks that could not be scheduled. The schedule also contains a lot of additional details such as the resources that were reserved and the causes of any delays in the schedule.

Tip All schedules are timezone agnostic. When you need to calculate occurrences, you can decide to perform the calculation using local time or UTC.

  // set later to use UTC time (the default)
  schedule.date.UTC();

  // set later to use local time
  schedule.date.localTime();

Once the tasks and resources have been defined, creating a new schedule is done using schedule.create.

schedule.create(tasks, resources, schedule, start)

Generates a new schedule for each of the tasks, reserving resources as required. The schedules generated will always occur at valid times according to the Later schedule specified and will start no earlier than start.

  // Define a set of tasks
  var tasks = [
    {id: 1, duration: 60, available: later.parse.text('every weekday')},
    {id: 2, duration: 30, dependsOn: [1], resources: ['A']},
    {id: 3, duration: 30, dependsOn: [1], resources: [['A','B']]}
  ];

  // Define a set of resources
  var resources = [
    {id: A},
    {id: B, available: later.parse.text('after 10:00am and before 6:00pm')}
  ];

  // Create the schedule for all of the tasks
  schedule.create(tasks, resources, later.parse.text('every weekday'), new Date());

Creating a new schedule produces a JSON object with a lot of details pertaining to the schedule that was created. Here we'll take a quick look at the results from the work item example.

Schedule object

The schedule object is returned from schedule.create and contains summary information about the schedule. The set of tasks that was successfully scheduled is returned as a map in scheduledTasks (described fully below). Any tasks that could not be scheduled are listed in the failedTasks array. If there were no failures, success will be true. The start time is the earliest time that any task was scheduled to start and end is the latest finishing time of any task.

Note All dates are returned as milliseconds from the Unix epoch, you can convert them to dates using new Date(val);.

  { scheduledTasks: {...see below...}
    failedTasks: null,
    success: true,
    start: 1364050800000,
    end: 1364157000000 }

Scheduled Tasks

The scheduledTasksis a map that contains one entry for each task that was successfully scheduled. The key is the task id. The value is an object containing an array of schedule items (described fully below), the total duration of the task, and a summary of the schedule.

The summary includes the first time the task is scheduled for (earlyStart), the time the task is scheduled to finish (earlyFinish), and the earliest time that a dependent task requires this task to be complete (lateFinish).

The float is the difference between the lateFinish and the earlyFinish in minutes. Any tasks that has a float of 0 are in the critical path which means any slip in the completion of this task will cause the schedule end date to slip as well.

  { 'Purchase supplies':
    { schedule: [...see below...],
      duration: 120,
      earlyStart: 1364058000000,
      earlyFinish: 1364065200000,
      lateFinish: 1364067000000,
      floatAmt: 30
    },
    ...
  }

Task schedule

The task scheduleis an array of times that the task has been scheduled for. It is returned as an array since a task can be broken up into multiple segments to better fit the schedule.

Each segment includes the set of resources that was reserved, the start and end times of the segment, the duration of the segment, and a list of delays which are fully described below.

  [
    {
      resources: [ 'Bob', 'Sara' ],
      start: 1364058000000,
      end: 1364065200000,
      duration: 120,
      success: true,
      delays: {...see below...}
    },
    ...
 ]

Delays

The delays list is a list of the things that caused a task segment to not start as soon as all of its dependencies were met. In this example, the task itself was not available, nor were Bob or Sara (all due to the available scheduled defined for them).

  {
    '_taskPurchase supplies':
      { needed: 1363849200000,
        available: 1363878000000 },
    Bob:
      { needed: 1363849200000,
        available: 1364058000000 },
    Sara:
      { needed: 1363849200000,
        available: 1364050800000 }
  }