diff --git a/app/models/conference.rb b/app/models/conference.rb
index f1a4fa5..6ec49ee 100644
--- a/app/models/conference.rb
+++ b/app/models/conference.rb
@@ -8,21 +8,13 @@ class Conference < ActiveRecord::Base
 
   translates :title, :description
 
-  has_many :tracks, -> { order('id asc') }, dependent: :destroy
-  has_many :events, through: :tracks
-  has_many :candidate_speakers, through: :events
-  has_many :halls, dependent: :destroy
+  has_many :tracks
+  has_many :halls
 
   accepts_nested_attributes_for :tracks, :halls, reject_if: :all_blank, allow_destroy: true
 
-  before_save :close_all_other_calls_for_papers
-
   private
 
-  def close_all_other_calls_for_papers
-    Conference.where.not(id: self.id).update_all call_for_papers_open: false
-  end
-
   def start_date_is_before_end_date
     if start_date.present? and end_date.present? and start_date > end_date
       errors.add(:end_date, :cannot_be_before_start_date)
diff --git a/spec/factories/halls.rb b/spec/factories/halls.rb
new file mode 100644
index 0000000..0e97cd3
--- /dev/null
+++ b/spec/factories/halls.rb
@@ -0,0 +1,8 @@
+# Read about factories at https://github.com/thoughtbot/factory_girl
+
+FactoryGirl.define do
+  factory :hall do
+    name { |n| "Hall#{n}" }
+    conference
+  end
+end
diff --git a/spec/factories/tracks.rb b/spec/factories/tracks.rb
index 156e920..c6b79d5 100644
--- a/spec/factories/tracks.rb
+++ b/spec/factories/tracks.rb
@@ -4,6 +4,7 @@ FactoryGirl.define do
   factory :track do
     name { |n| "Track#{n}" }
     color '#000000'
+    description 'Some description'
     conference
   end
 end
diff --git a/spec/models/conference_spec.rb b/spec/models/conference_spec.rb
index d7ec8d7..d615b52 100644
--- a/spec/models/conference_spec.rb
+++ b/spec/models/conference_spec.rb
@@ -50,4 +50,70 @@ RSpec.describe Conference, :type => :model do
   it 'is invalid when the end date is before the start date' do
     expect(build(:conference, start_date: '2014-07-29 21:29:13', end_date: '2014-07-28 01:00:00')).to have_error_on :end_date
   end
+
+  describe 'tracks association' do
+    let(:conference) { build :conference }
+    let(:track) { build :track }
+
+    before do
+      conference.save
+      track.conference = conference
+      track.save
+    end
+
+    it 'links the conference to its tracks' do
+      expect(conference.tracks).to include track
+    end
+  end
+
+  describe 'halls association' do
+    let(:conference) { build :conference }
+    let(:hall) { build :hall }
+
+    before do
+      conference.save
+      hall.conference = conference
+      hall.save
+    end
+
+    it 'has many associated halls' do
+      expect(conference.halls).to include hall
+    end
+  end
+
+  it 'accepts nested attributes for tracks' do
+    track_attributes = build(:track, conference: nil).attributes
+    conference = create :conference
+    expect { conference.update tracks_attributes: [track_attributes]}.to change { conference.tracks.count }.by 1
+  end
+
+  it 'rejects nested attributes for tracks when they are all blank' do
+    conference = create :conference
+    expect { conference.update tracks_attributes: [{'name' => '', 'description' => ''}]}.to_not change { conference.tracks.count }
+  end
+
+  it 'allows destruction of tracks by nested attributes' do
+    conference = create :conference
+    track_attributes = create(:track, conference: conference).attributes
+    track_attributes['_destroy'] = 1
+    expect { conference.update tracks_attributes: [track_attributes]}.to change { conference.tracks.count }.by(-1)
+  end
+
+  it 'accepts nested attributes for halls' do
+    hall_attributes = build(:hall, conference: nil).attributes
+    conference = create :conference
+    expect { conference.update halls_attributes: [hall_attributes]}.to change { conference.halls.count }.by 1
+  end
+
+  it 'rejects nested attributes for halls when they are all blank' do
+    conference = create :conference
+    expect { conference.update halls_attributes: [{'name' => '', 'description' => ''}]}.to_not change { conference.halls.count }
+  end
+
+  it 'allows destruction of halls by nested attributes' do
+    conference = create :conference
+    hall_attributes = create(:hall, conference: conference).attributes
+    hall_attributes['_destroy'] = 1
+    expect { conference.update halls_attributes: [hall_attributes]}.to change { conference.halls.count }.by(-1)
+  end
 end