Creating Gantt charts by Exporting to TaskJuggler

Introduction

Org mode is an excellent tool for project planning as Peter Jones has shown in his article on project planning. He first breaks the project into features and tasks, then estimates the effort and from that presents a project plan. In this tutorial we will take this one step further, assign resources to the tasks, schedule the tasks and create the corresponding gantt chart for this project.

We will be using TaskJuggler to handle the task scheduling, resource leveling and creation of a myriad of charts (such as Gantt chart) for your customer or your Pointy-haired Boss.

Plan your project

You start out as you normally would by breaking down the project into tasks. Let's take the following example where you have a project to create an accounting software:

* Accounting Software

** Specification

** Software Development
*** Database coupling
*** Back-End Functions
*** Graphical User Interface

** Software testing
*** Alpha Test
*** Beta Test

** Manual

** Milestones
*** Project start
*** Technology Preview
*** Beta version
*** Ship Product to Customer

Estimate the effort

Now that you've figured out the tasks it's time to estimate the efforts for each task. By using column view this can be done very efficiently. It also helps to define the COLUMNS and default values for the Effort property as shown in the following screen shot:

Figure 1: Estimating effort using column view

Your resulting Org mode project file will look somewhat like the following:

#+PROPERTY: Effort_ALL 2d 5d 10d 20d 30d 35d 50d
#+COLUMNS: %70ITEM(Task) %Effort

* Accounting Software

** Specification
   :PROPERTIES:
   :Effort:   20d
   :END:

** Software Development

*** Database coupling
    :PROPERTIES:
    :Effort:   20d
    :END:

*** Back-End Functions
    :PROPERTIES:
    :Effort:   30d
    :END:

*** Graphical User Interface
    :PROPERTIES:
    :Effort:   35d
    :END:

** Software testing
*** Alpha Test
    :PROPERTIES:
    :Effort:   5d
    :END:

*** Beta Test
    :PROPERTIES:
    :Effort:   20d
    :END:

** Manual
   :PROPERTIES:
   :Effort:   50d
   :END:

** Milestones
*** Project start
*** Technology Preview
*** Beta version
*** Ship Product to Customer

Generate a Gantt chart

Before you now export the project to TaskJuggler you need to tell the exporter in which tree it can find the tasks. You do this by adding the tag taskjuggler_project to the node "Accounting Software"¹. Do this by moving to the "Accounting Software" headline and typing the following:

C-c C-c taskjuggler_project RET

This allows you to have other nodes for this project such as an introduction or general notes.

To export the project to TaskJuggler you simply type

M-x org-export-as-taskjuggler-and-open

This will open your project in TaskJugglerUI as illustrated below

Since we have not assigned any resources to work on the project the exporter assumes that you will be the one working on it and has assigned all tasks to you. The tasks have been serialized so that you will not have to many things to do at once, i.e. the resources will be leveled.

Assign resources

The next step is to list all the resources working on the project and assign the tasks to them. Create a node for the resources. You can group the resources by creating hierarchies. Tag the resource tree with the tag taskjuggler_resource so that the exporter knows where to look for resource definitions².

* Resources                                         :taskjuggler_resource:
** Developers
   :PROPERTIES:
   :resource_id: dev
   :END:
*** Paul Smith
    :PROPERTIES:
    :resource_id: paul
    :END:
*** Sébastien Bono
    :PROPERTIES:
    :resource_id: seb
    :END:
*** Klaus Müller

** Others
*** Peter Murphy
    :PROPERTIES:
    :resource_id: doc
    :END:
*** Dim Sung
    :PROPERTIES:
    :resource_id: test
    :END:

As you'll note I also added some resource_id properties to some of the resources (or resource groups). I will use these identifiers to allocate the resources to the tasks. The exporter will create unique ids for the resources automatically³, but if you want to use short forms it's better to define resource_id properties for your resources. This will also allow you to define default values for the allocation as follows:

#+PROPERTY: allocate_ALL dev doc test

The easiest way to assign resources is again the column view mode. There is no need to allocate a resource to every task, as allocations are inherited in TaskJuggler⁴. You'll note in the screen shot below that some tasks have more than one resource assigned to them. TaskJuggler will calculate the duration of the task based on the effort and the resources working on this task.

If we now export the project you'll see that TaskJuggler scheduled some tasks in parallel (as there are several resources now which can work in parallel). See the screen shot below:

Figure 4: Gantt Chart with multiple resources

Obviously we need to define dependencies between the tasks.

Define dependencies

There are several ways to define dependencies between tasks. When coming from an Org mode background you probably want to define them using the facilities provided by Org mode, which are either

The ORDERED property which allows you to state that the child tasks have to be completed in the order they appear (top most first).
The BLOCKER property which allows you to state that a task depends on either
- a previous sibling ("previous-sibling") or
- any other task by stating the task_id property of the predecessor

Again, it is probably easiest to define the dependencies using the column view as shown below in the screen shot:

Figure 5: Defining dependencies using column view

Lastly there is also the depends property which corresponds to the TaskJuggler terminology. It can be used the same way as the BLOCKER property. This is illustrated below where the "Software Development" for example is blocked by the task "Specification", i.e. it has to wait until the specification is done. The task "Software Development" is defined as ORDERED, i.e. all the subtasks of it have to be completed in sequence. Another example is the milestone "Ship Product to Customer" which is waiting until the Beta test and the Manual are done.

#+PROPERTY: Effort_ALL 2d 5d 10d 20d 30d 35d 50d
#+PROPERTY: allocate_ALL dev doc test
#+COLUMNS: %30ITEM(Task) %Effort %allocate %BLOCKER %ORDERED

* Accounting Software                                        :taskjuggler_project:

** Specification
   :PROPERTIES:
   :Effort:   20d
   :BLOCKER:  start
   :allocate: dev
   :END:

** Software Development
   :PROPERTIES:
   :ORDERED:  t
   :BLOCKER:  previous-sibling
   :priority: 1000
   :allocate: dev
   :END:

*** Database coupling
    :PROPERTIES:
    :Effort:   20d
    :END:

*** Back-End Functions
    :PROPERTIES:
    :Effort:   30d
    :task_id:  back_end
    :END:

*** Graphical User Interface
    :PROPERTIES:
    :Effort:   35d
    :allocate: paul, seb
    :END:

** Software testing
   :PROPERTIES:
   :ORDERED:  t
   :BLOCKER:  previous-sibling
   :allocate: test
   :END:
*** Alpha Test
    :PROPERTIES:
    :Effort:   5d
    :task_id:  alpha
    :END:

*** Beta Test
    :PROPERTIES:
    :Effort:   20d
    :task_id:  beta
    :allocate: test, paul
    :END:

** Manual
   :PROPERTIES:
   :Effort:   50d
   :task_id:  manual
   :BLOCKER:  start
   :allocate: doc
   :END:

** Milestones
*** Project start
    :PROPERTIES:
    :task_id:  start
    :END:

*** Technology Preview
    :PROPERTIES:
    :BLOCKER:  back_end
    :END:

*** Beta version
    :PROPERTIES:
    :BLOCKER:  alpha
    :END:

*** Ship Product to Customer
    :PROPERTIES:
    :BLOCKER:  beta manual
    :END:


* Resources                                         :taskjuggler_resource:
** Developers
   :PROPERTIES:
   :resource_id: dev
   :END:
*** Paul Smith
    :PROPERTIES:
    :resource_id: paul
    :END:
*** Sébastien Bono
    :PROPERTIES:
    :resource_id: seb
    :END:
*** Klaus Müller

** Others
*** Peter Murphy
    :PROPERTIES:
    :resource_id: doc
    :limits:   { dailymax 6.4h }
    :END:
*** Dim Sung
    :PROPERTIES:
    :resource_id: test
    :END:

If you export the example above you'll TaskJuggler will schedule the tasks as shown in the screen shot below

Also TaskJuggler will give you a overview how busy youre resources will be and what they are working on. See below for a screen shot:

Finally you can generate good-looking project plans in PDF by printing from TaskJuggler. This will make any Pointy-haired Boss happy.

Export of other properties

Generally the exporter writes a node property that is known to TaskJuggler (such as shift, booking, efficiency, journalentry, rate for resources or account, start, note, duration, end, journalentry, milestone, reference, responsible, scheduling, etc for tasks) as is to the TaskJuggler file.

Other properties such as completeness or priority are derived from implicit information in the Org mode file. The TODO state for example determines the completeness. A task will be exported with 100% complete (complete 100) if it is marked as done. The priority of a task will be determined through its priority cookie.

Footnotes:

You can customize this tag

Again, of course this tag can be customized

by downcasing the headline, replacing non-ascii characters with '_' and picking the first word if it is unique

⁴

In TaskJuggler the allocations are cumulative, the exporter however adds some code so that inherited allocation are ignored when explicitly assigning a resource.