diff --git a/.gitignore b/.gitignore
index 47302a67..c2d5f548 100644
--- a/.gitignore
+++ b/.gitignore
@@ -3,3 +3,4 @@ Gemfile.lock
 coverage
 .ruby-gemset
 .ruby-version
+gemfiles/*.gemfile.lock
diff --git a/.travis.yml b/.travis.yml
index 3351b5e2..8c8ad0c6 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -1,13 +1,29 @@
 ---
+sudo: required
+dist: trusty
+
 language: ruby
-sudo: false
-cache: bundler
-before_script:
-  - sh -e /etc/init.d/xvfb start
-  - export DISPLAY=:99.0
-  - bundle exec rake test_app
+
+env:
+  - DB=postgres
+  - DB=mysql
+
+gemfile:
+  - gemfiles/spree_3_1.gemfile
+  - gemfiles/spree_3_2.gemfile
+  - gemfiles/spree_master.gemfile
+
 script:
-  - bundle exec rspec spec
+  - bundle exec rake test_app
+  - bundle exec rake spec
+
 rvm:
-  - 2.2.4
-  - 2.3.0
+  - 2.3.1
+  - 2.2.5
+
+addons:
+  apt:
+    packages:
+    - mysql-server-5.6
+    - mysql-client-core-5.6
+    - mysql-client-5.6
diff --git a/Appraisals b/Appraisals
new file mode 100644
index 00000000..1c5a9816
--- /dev/null
+++ b/Appraisals
@@ -0,0 +1,13 @@
+appraise 'spree-3-1' do
+  gem 'spree', '~> 3.1.0'
+end
+
+appraise 'spree-3-2' do
+  gem 'spree', '~> 3.2.0'
+  gem 'rails-controller-testing'
+end
+
+appraise 'spree-master' do
+  gem 'spree', github: 'spree/spree', branch: 'master'
+  gem 'rails-controller-testing'
+end
diff --git a/Gemfile b/Gemfile
index 978cef5b..aa91e542 100644
--- a/Gemfile
+++ b/Gemfile
@@ -2,6 +2,4 @@ source "https://rubygems.org"
 
 gem 'spree', github: 'spree/spree', branch: 'master'
 
-gem 'pry-rails'
-
 gemspec
diff --git a/app/models/spree/order_decorator.rb b/app/models/spree/order_decorator.rb
new file mode 100644
index 00000000..f62923ca
--- /dev/null
+++ b/app/models/spree/order_decorator.rb
@@ -0,0 +1,14 @@
+module Spree
+  Order.class_eval do
+    after_update :clean_inventory_units
+
+    # during checkout each inventory_unit is saved twice
+    # second unit is not associated to shipment and is unnecessary
+    def clean_inventory_units
+      if state == 'delivery'
+        units = inventory_units.where(shipment: nil)
+        InventoryUnit.destroy(units.ids) if units.any?
+      end
+    end
+  end
+end
diff --git a/app/models/spree/order_inventory_assembly.rb b/app/models/spree/order_inventory_assembly.rb
index 6f0a7334..3df6be85 100644
--- a/app/models/spree/order_inventory_assembly.rb
+++ b/app/models/spree/order_inventory_assembly.rb
@@ -9,6 +9,7 @@ def initialize(line_item)
       @order = line_item.order
       @line_item = line_item
       @product = line_item.product
+      @variant = line_item.variant
     end
 
     def verify(shipment = nil)
@@ -25,6 +26,32 @@ def verify(shipment = nil)
 
     private
 
+    def add_to_shipment(shipment, quantity)
+      units = shipment.inventory_units
+      if variant.should_track_inventory?
+        on_hand, back_order = shipment.stock_location.fill_status(variant, quantity)
+
+        on_hand.times { units << set_up_invetory_unit('on_hand', variant, order, line_item) }
+        back_order.times { units << set_up_invetory_unit('backordered', variant, order, line_item) }
+      else
+        quantity.times { units << set_up_invetory_unit('on_hand', variant, order, line_item) }
+      end
+
+      shipment.inventory_units = units
+      shipment.save
+
+      # adding to this shipment, and removing from stock_location
+      if order.completed?
+        shipment.stock_location.unstock(variant, quantity, shipment)
+      end
+
+      quantity
+    end
+
+    def set_up_invetory_unit(state, variant, order, line_item)
+      InventoryUnit.new(state: state, variant_id: variant.id, order_id: order.id, line_item_id: line_item.id)
+    end
+
     def verify_parts(shipment, total_parts, existing_parts)
       if existing_parts < total_parts
         verifiy_add_to_shipment(shipment, total_parts, existing_parts)
diff --git a/app/models/spree/stock/coordinator_decorator.rb b/app/models/spree/stock/coordinator_decorator.rb
new file mode 100644
index 00000000..71aa0625
--- /dev/null
+++ b/app/models/spree/stock/coordinator_decorator.rb
@@ -0,0 +1,45 @@
+module Spree
+  module Stock
+    Coordinator.class_eval do
+      attr_reader :allocated_inventory_units
+
+      def initialize(order, inventory_units = nil)
+        @order = order
+        @inventory_units = inventory_units || InventoryUnitBuilder.new(order).units
+        @allocated_inventory_units = []
+      end
+
+      def build_packages(packages = Array.new)
+        stock_locations_with_requested_variants.each do |stock_location|
+          packer = build_packer(stock_location, unallocated_inventory_units)
+          packages += packer.packages
+          @allocated_inventory_units += packer.allocated_inventory_units
+        end
+
+        packages
+      end
+
+      private
+
+      def unallocated_inventory_units
+        if inventory_units.map(&:id).include?(nil)
+          allocated_inventory_units.each do |allocated|
+            inventory_units.each_with_index do |unit, index|
+              if should_delete_item?(allocated, unit)
+                inventory_units.delete_at(index)
+                break
+              end
+            end
+          end
+          inventory_units
+        else
+          inventory_units - allocated_inventory_units
+        end
+      end
+
+      def should_delete_item?(allocated, unit)
+        allocated.line_item_id == unit.line_item_id && allocated.variant_id == unit.variant_id
+      end
+    end
+  end
+end
diff --git a/app/models/spree/stock/packer_decorator.rb b/app/models/spree/stock/packer_decorator.rb
new file mode 100644
index 00000000..41f39b11
--- /dev/null
+++ b/app/models/spree/stock/packer_decorator.rb
@@ -0,0 +1,33 @@
+module Spree
+  module Stock
+    Packer.class_eval do
+      attr_reader :allocated_inventory_units
+
+      def initialize(stock_location, inventory_units, splitters = [Splitter::Base])
+        @stock_location = stock_location
+        @inventory_units = inventory_units
+        @splitters = splitters
+        @allocated_inventory_units = []
+      end
+
+      def default_package
+        package = Package.new(stock_location)
+
+        inventory_units.each do |inventory_unit|
+          variant = inventory_unit.variant
+          unit = inventory_unit.dup # Can be used by others, do not use directly
+          if variant.should_track_inventory?
+            next unless stock_location.stock_item(variant)
+            on_hand, backordered = stock_location.fill_status(variant, 1)
+            package.add(unit, :backordered) if backordered > 0
+            package.add(unit, :on_hand) if on_hand > 0
+          else
+            package.add unit
+          end
+          allocated_inventory_units << unit
+        end
+        package
+      end
+    end
+  end
+end
\ No newline at end of file
diff --git a/app/models/spree/stock/prioritizer_decorator.rb b/app/models/spree/stock/prioritizer_decorator.rb
new file mode 100644
index 00000000..ba025ed7
--- /dev/null
+++ b/app/models/spree/stock/prioritizer_decorator.rb
@@ -0,0 +1,18 @@
+module Spree
+  module Stock
+    Prioritizer.class_eval do
+
+      private
+
+      def hash_item(item)
+        shipment = item.inventory_unit.shipment
+        inventory_unit = item.inventory_unit
+        if shipment.present?
+          inventory_unit.hash ^ shipment.hash
+        else
+          inventory_unit.hash
+        end
+      end
+    end
+  end
+end
\ No newline at end of file
diff --git a/gemfiles/spree_3_1.gemfile b/gemfiles/spree_3_1.gemfile
new file mode 100644
index 00000000..925b090b
--- /dev/null
+++ b/gemfiles/spree_3_1.gemfile
@@ -0,0 +1,7 @@
+# This file was generated by Appraisal
+
+source "https://rubygems.org"
+
+gem "spree", "~> 3.1.0"
+
+gemspec :path => "../"
diff --git a/gemfiles/spree_3_2.gemfile b/gemfiles/spree_3_2.gemfile
new file mode 100644
index 00000000..844fc70a
--- /dev/null
+++ b/gemfiles/spree_3_2.gemfile
@@ -0,0 +1,8 @@
+# This file was generated by Appraisal
+
+source "https://rubygems.org"
+
+gem "spree", "~> 3.2.0"
+gem "rails-controller-testing"
+
+gemspec :path => "../"
diff --git a/gemfiles/spree_master.gemfile b/gemfiles/spree_master.gemfile
new file mode 100644
index 00000000..c382de2c
--- /dev/null
+++ b/gemfiles/spree_master.gemfile
@@ -0,0 +1,8 @@
+# This file was generated by Appraisal
+
+source "https://rubygems.org"
+
+gem "spree", :github => "spree/spree", :branch => "master"
+gem "rails-controller-testing"
+
+gemspec :path => "../"
diff --git a/spec/features/admin/orders_spec.rb b/spec/features/admin/orders_spec.rb
index 11509893..3aaad281 100644
--- a/spec/features/admin/orders_spec.rb
+++ b/spec/features/admin/orders_spec.rb
@@ -8,7 +8,7 @@
 
   background do
     bundle.master.parts << [parts]
-    line_item.update_attributes!(quantity: 3)
+    line_item.reload.update_attributes!(quantity: 3)
     order.reload.create_proposed_shipments
     order.finalize!
   end
diff --git a/spec/models/spree/assign_part_to_bundle_form_spec.rb b/spec/models/spree/assign_part_to_bundle_form_spec.rb
index 61fd58dd..acf001b1 100644
--- a/spec/models/spree/assign_part_to_bundle_form_spec.rb
+++ b/spec/models/spree/assign_part_to_bundle_form_spec.rb
@@ -17,7 +17,7 @@ module Spree
           bundle = create(:product)
           part = create(:product, can_be_part: true)
           assignment = AssembliesPart.create(
-            assembly_id: bundle.id,
+            assembly_id: bundle.master.id,
             count: 1,
             part_id: part.id
           )
@@ -37,7 +37,7 @@ module Spree
           bundle = create(:product)
           part = create(:product, can_be_part: true)
 
-          part_options = { count: 2, part_id: part.id, assembly_id: bundle.id }
+          part_options = { count: 2, part_id: part.id, assembly_id: bundle.master.id }
 
           command = AssignPartToBundleForm.new(bundle, part_options)
 
diff --git a/spec/models/spree/order_contents_spec.rb b/spec/models/spree/order_contents_spec.rb
index 5933b390..c6bb6a82 100644
--- a/spec/models/spree/order_contents_spec.rb
+++ b/spec/models/spree/order_contents_spec.rb
@@ -50,10 +50,10 @@
         create(:variant_in_stock, product: shirt, option_values: [blue_option])
 
         assembly_part_keychain = create(:assemblies_part,
-               assembly_id: assembly.id,
+               assembly_id: assembly.master.id,
                part_id: keychain.master.id)
         assembly_part_shirt = create(:assemblies_part,
-               assembly_id: assembly.id,
+               assembly_id: assembly.master.id,
                part_id: shirt.master.id,
                variant_selection_deferred: true)
         assembly.reload
diff --git a/spec/models/spree/order_inventory_assembly_spec.rb b/spec/models/spree/order_inventory_assembly_spec.rb
index b7c087de..d8f95742 100644
--- a/spec/models/spree/order_inventory_assembly_spec.rb
+++ b/spec/models/spree/order_inventory_assembly_spec.rb
@@ -146,30 +146,44 @@ module Spree
                   line_item_quantity: 2,
                   parts: [{ count: 1 }, { count: 1 }, { count: 3 }]
                 )
+
                 shipped_shipment = create(:shipment, state: 'shipped')
-                InventoryUnit.all[0..2].each do |unit|
+                shipped_variant = variants.first
+                shipped = InventoryUnit.where(variant: shipped_variant)
+
+                shipped.each do |unit|
                   unit.update_attribute(:shipment_id, shipped_shipment.id)
+                  unit.update_attribute(:state, 'shipped')
                 end
 
-                inventory = OrderInventoryAssembly.new(line_item)
+                new_quantity = 1
 
-                line_item.update_column(:quantity, 1)
-                inventory.verify
+                line_item.update_column(:quantity, new_quantity)
+                line_item.reload
 
-                expect(inventory.inventory_units.count).to eq 6
+                inventory = OrderInventoryAssembly.new(line_item)
+                inventory.verify
 
                 unshipped_units = unshipped_shipment.inventory_units
-                expect(unshipped_units.count).to eq 3
+                shipped_units = shipped_shipment.inventory_units
+
+                units_last_variant = new_quantity * variants.last.assemblies_variants.first.count
+                units_second_variant = new_quantity * variants.second.assemblies_variants.first.count
+                units_first_variant = shipped.count
+
+                expected_units_count = units_first_variant + units_second_variant + units_last_variant
+
+                expect(inventory.inventory_units.count).to eq expected_units_count
+
+                expect(unshipped_units.count).to eq(expected_units_count - shipped.count)
                 unshipped_units.each do |unit|
-                  expect(unit.variant).to eq variants[2]
+                  expect(unit.variant).not_to eq shipped_variant
                 end
 
-                shipped_units = shipped_shipment.inventory_units
-                expect(shipped_units.count).to eq 3
-                shipped_units[0..1].each do |unit|
-                  expect(unit.variant).to eq variants[0]
+                expect(shipped_units.count).to eq(shipped.count)
+                shipped_units.each do |unit|
+                  expect(unit.variant).to eq shipped_variant
                 end
-                expect(shipped_units[2].variant).to eq variants[1]
               end
             end
           end
diff --git a/spec/models/spree/order_spec.rb b/spec/models/spree/order_spec.rb
new file mode 100644
index 00000000..9614e28c
--- /dev/null
+++ b/spec/models/spree/order_spec.rb
@@ -0,0 +1,56 @@
+module Spree
+  describe Order, type: :model do
+
+    let(:order) { create(:order_with_line_items) }
+    let(:line_item) { order.line_items.first }
+    let(:bundle) { line_item.product }
+    let(:parts) { (1..3).map { create(:variant) } }
+
+    before do
+      bundle.master.parts << [parts]
+      order.contents.update_cart({line_items_attributes: {
+        id: line_item.id,
+        quantity: 3,
+        options: {}
+      }})
+      order.next
+      order.reload.create_proposed_shipments
+      order.finalize!
+    end
+
+    context "product assembly is added to shipment of completed order" do
+      it "sets items number bigger than existing item number - adds inventory units to shipment package" do
+        order.contents.update_cart({line_items_attributes: {
+          id: line_item.id,
+          quantity: 4,
+          options: {}
+        }})
+
+        line_item_quantity = line_item.reload.quantity
+        units_quantity = 0
+        order.reload.shipments.each { |s| units_quantity += s.inventory_units.count }
+
+        expect(line_item_quantity).to eq(4)
+        expect(units_quantity).to eq(4 * 3)
+      end
+    end
+
+    context "product assembly is removed from shipment of completed order" do
+      it "sets items number lower than existing item number - removes inventory units from shipment package" do
+
+        order.contents.update_cart({line_items_attributes: {
+                id: line_item.id,
+                quantity: 1,
+                options: {}
+            }})
+
+        line_item_quantity = line_item.reload.quantity
+        units_quantity = 0
+        order.reload.shipments.each { |s| units_quantity += s.inventory_units.count }
+
+        expect(line_item_quantity).to eq(1)
+        expect(units_quantity).to eq(1 * 3)
+      end
+    end
+  end
+end
diff --git a/spree_product_assembly.gemspec b/spree_product_assembly.gemspec
index 3a0fc2d8..70b7993f 100644
--- a/spree_product_assembly.gemspec
+++ b/spree_product_assembly.gemspec
@@ -17,18 +17,21 @@ Gem::Specification.new do |s|
 
   s.add_dependency 'spree_backend', '>= 3.1.0', '< 4.0'
 
-  s.add_development_dependency 'active_model_serializers', '~> 0.8.3'
-  s.add_development_dependency 'capybara', '~> 2.5'
-  s.add_development_dependency 'capybara-screenshot', '~> 1.0.11'
-  s.add_development_dependency 'coffee-rails', '~> 4.0.0'
-  s.add_development_dependency 'database_cleaner', '~> 1.4'
-  s.add_development_dependency 'factory_girl', '~> 4.4'
+  s.add_development_dependency 'active_model_serializers'
+  s.add_development_dependency 'capybara'
+  s.add_development_dependency 'capybara-screenshot'
+  s.add_development_dependency 'coffee-rails'
+  s.add_development_dependency 'database_cleaner'
+  s.add_development_dependency 'factory_girl'
   s.add_development_dependency 'ffaker'
   s.add_development_dependency 'launchy'
   s.add_development_dependency 'pg'
-  s.add_development_dependency 'poltergeist', '~> 1.6'
-  s.add_development_dependency 'rspec-rails', '~> 3.4.0'
-  s.add_development_dependency 'sass-rails', '~> 5.0.0'
+  s.add_development_dependency 'poltergeist'
+  s.add_development_dependency 'rspec-rails'
+  s.add_development_dependency 'sass-rails'
   s.add_development_dependency 'simplecov'
   s.add_development_dependency 'sqlite3'
+  s.add_development_dependency 'mysql2'
+  s.add_development_dependency 'pry-rails'
+  s.add_development_dependency 'appraisal'
 end