diff --git a/app/models/task.rb b/app/models/task.rb
index c64096d..1f64f1a 100644
--- a/app/models/task.rb
+++ b/app/models/task.rb
@@ -1,4 +1,85 @@
+# Task is the base class of ... tasks! Its instances represents tasks that must
+# be confirmed by someone (like an environment administrator) or by noosfero
+# itself.
+#
+# The specific types of tasks <em>must</em> override the #perform method, so
+# the actual action associated to the type of task can be performed. See the
+# documentation of the #perform method for details. 
+#
+# This class has a +status+ field of type <tt>text</tt>, where you can store
+# any type of data (as serialized Ruby objects) you need for your subclass .
 class Task < ActiveRecord::Base
+
+  module Status
+    # the status of tasks just created
+    ACTIVE = 1
+
+    # the status of a task that was cancelled.
+    CANCELLED = 2
+
+    # the status os a task that was successfully finished
+    FINISHED = 3
+  end
+
   belongs_to :requestor, :class_name => 'Profile', :foreign_key => :requestor_id
   belongs_to :target, :class_name => 'Profile', :foreign_key => :target_id
+
+  def initialize(*args)
+    super
+    self.status ||= Task::Status::ACTIVE
+  end
+
+  # this method finished the task. It calls #perform, which must be overriden
+  # by subclasses. At the end a message (as returned by #finish_message) is
+  # sent to the requestor with #notify_requestor.
+  def finish
+    transaction do
+      self.status = Task::Status::FINISHED
+      self.end_date = Time.now
+      self.save!
+      self.perform
+      self.notify_requestor(self.finish_message)
+    end
+  end
+
+  # this method cancels the task. At the end a message (as returned by
+  # #cancel_message) is sent to the requestor with #notify_requestor.
+  def cancel
+    transaction do
+      self.status = Task::Status::CANCELLED
+      self.end_date = Time.now
+      self.save!
+      self.notify_requestor(self.cancel_message)
+    end
+  end
+
+  protected
+
+  # This method must be overrided in subclasses, and its implementation must do
+  # the job the task is intended to. This method will be called when the finish
+  # method is called.
+  #
+  # To cancel the finish of the task, you can throw an exception in perform.
+  #
+  # The implementation on Task class just does nothing.
+  def perform
+  end
+
+  # sends a message to the requestor
+  def notify_requestor(msg)
+    # TODO: implement message sending
+  end
+
+  # The message that will be sent to the requestor of the task when its
+  # finished.
+  def finish_message
+    _("The task was finished at %s") % (self.end_date.to_s)
+  end
+
+  # The message that will be sent to the requestor of the task when its
+  # cancelled.
+  def cancel_message
+    _("The task was cancelled at %s") % (self.end_date.to_s)
+  end
+
 end
diff --git a/db/migrate/017_create_tasks.rb b/db/migrate/017_create_tasks.rb
index 6ca2f4a..5c045ae 100644
--- a/db/migrate/017_create_tasks.rb
+++ b/db/migrate/017_create_tasks.rb
@@ -1,9 +1,11 @@
 class CreateTasks < ActiveRecord::Migration
   def self.up
     create_table :tasks do |t|
+      t.column :description, :string
 
       t.column :data, :text
       t.column :status, :integer
+      t.column :end_date, :date
 
       t.column :requestor_id, :integer
       t.column :target_id, :integer
diff --git a/test/unit/task_test.rb b/test/unit/task_test.rb
index ef07fb6..40e3b63 100644
--- a/test/unit/task_test.rb
+++ b/test/unit/task_test.rb
@@ -3,7 +3,7 @@ require File.dirname(__FILE__) + '/../test_helper'
 class TaskTest < Test::Unit::TestCase
 
   def test_relationship_with_requestor
-    t = Task.new
+    t = Task.create
     assert_raise ActiveRecord::AssociationTypeMismatch do
       t.requestor = 1
     end
@@ -13,7 +13,7 @@ class TaskTest < Test::Unit::TestCase
   end
 
   def test_relationship_with_target
-    t = Task.new
+    t = Task.create
     assert_raise ActiveRecord::AssociationTypeMismatch do
       t.target = 1
     end
@@ -21,4 +21,53 @@ class TaskTest < Test::Unit::TestCase
       t.target = Profile.new
     end
   end
+
+  def test_should_call_perform_in_finish
+    t = Task.create
+    t.expects(:perform)
+    t.finish
+    assert_equal Task::Status::FINISHED, t.status
+  end
+
+  def test_should_have_cancelled_status_after_cancel
+    t = Task.create
+    t.cancel
+    assert_equal Task::Status::CANCELLED, t.status
+  end
+
+  def test_should_start_with_active_status
+    t = Task.create
+    assert_equal Task::Status::ACTIVE, t.status
+  end
+
+  def test_should_notify_finish
+    t = Task.create
+    t.expects(:notify_requestor)
+    t.expects(:finish_message)
+    t.finish
+  end
+
+  def test_should_notify_cancel
+    t = Task.create
+    t.expects(:notify_requestor)
+    t.expects(:cancel_message)
+    t.cancel
+  end
+
+  def test_should_not_notify_when_perform_fails
+    count = Task.count
+
+    t = Task.create
+    class << t
+      def perform
+        raise RuntimeError
+      end
+    end
+
+    t.expects(:notify_requestor).never
+    assert_raise RuntimeError do
+      t.finish
+    end
+  end
+
 end
--
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