diff --git a/app/controllers/statistics_controller.rb b/app/controllers/statistics_controller.rb
index 3d72bece..e05baadb 100644
--- a/app/controllers/statistics_controller.rb
+++ b/app/controllers/statistics_controller.rb
@@ -4,7 +4,7 @@ def sabeels
 
     @apts = {}
 
-    APARTMENTS.each do |apartment|
+    Sabeel::APARTMENTS.each do |apartment|
       total_sabeels = Sabeel.send(apartment)
       active_thaalis = total_sabeels.taking_thaali
       inactive = total_sabeels.not_taking_thaali
@@ -12,9 +12,7 @@ def sabeels
       @apts[apartment].store(:active_thaalis, active_thaalis.length)
       @apts[apartment].store(:total_sabeels, total_sabeels.length)
       @apts[apartment].store(:inactive_thaalis, inactive.length)
-      SIZES.each do |size|
-        @apts[apartment].store(size.to_sym, active_thaalis.with_thaali_size(size).length)
-      end
+      Thaali::SIZES.each { @apts[apartment].store(_1, active_thaalis.with_thaali_size(_1).length) }
     end
   end
 
@@ -32,9 +30,7 @@ def thaalis
       @years[y].store(:count, thaalis.count)
       @years[y].store(:pending, Thaali.dues_unpaid_for(y).length)
       @years[y].store(:complete, Thaali.dues_cleared_in(y).length)
-      SIZES.each do |size|
-        @years[y].store(size.to_sym, thaalis.send(size).count)
-      end
+      Thaali::SIZES.each { @years[y].store(_1, thaalis.send(_1).count) }
     end
   end
 end
diff --git a/app/controllers/thaalis_controller.rb b/app/controllers/thaalis_controller.rb
index 0fe84152..41e20d81 100644
--- a/app/controllers/thaalis_controller.rb
+++ b/app/controllers/thaalis_controller.rb
@@ -13,8 +13,7 @@ def new
 
     if @sabeel.took_thaali?
       took_thaali = @thaalis.where(year: PREV_YR).first
-      @thaali.number = took_thaali[:number]
-      @thaali.size = took_thaali[:size]
+      @thaali.attributes = took_thaali.slice(:number, :size)
     end
   end
 
@@ -24,7 +23,6 @@ def edit
   def create
     @sabeel = Sabeel.find(params[:sabeel_id])
     @thaali = @sabeel.thaalis.new(create_params)
-    @thaali.year = CURR_YR
 
     if @thaali.save
       Rails.cache.write("sabeel_#{@sabeel.id}_taking_thaali?", true)
diff --git a/app/models/concerns/array_extensions.rb b/app/models/concerns/array_extensions.rb
new file mode 100644
index 00000000..5091b163
--- /dev/null
+++ b/app/models/concerns/array_extensions.rb
@@ -0,0 +1,5 @@
+module ArrayExtensions
+  refine Array do
+    def to_h_titleize_value = to_h { [_1, _1.to_s.titleize] }
+  end
+end
diff --git a/app/models/role.rb b/app/models/role.rb
index 3a16d29c..3bff2656 100644
--- a/app/models/role.rb
+++ b/app/models/role.rb
@@ -1,18 +1,17 @@
 class Role < ApplicationRecord
+  # * Constants
+  NAMES = %w[admin member viewer]
+
   # rubocop:disable Rails/HasAndBelongsToMany
   has_and_belongs_to_many :users, join_table: :users_roles
   # rubocop:enable Rails/HasAndBelongsToMany
 
-  belongs_to :resource,
-    polymorphic: true,
-    optional: true
+  belongs_to :resource, polymorphic: true, optional: true
 
-  validates :resource_type,
-    inclusion: {in: Rolify.resource_types},
-    allow_nil: true
+  validates :resource_type, inclusion: {in: Rolify.resource_types}, allow_nil: true
 
   validates :name, presence: true
-  validates :name, inclusion: {in: ROLES}
+  validates :name, inclusion: {in: NAMES}
 
   scopify
 end
diff --git a/app/models/sabeel.rb b/app/models/sabeel.rb
index 8354bbc3..14f63b12 100644
--- a/app/models/sabeel.rb
+++ b/app/models/sabeel.rb
@@ -1,4 +1,10 @@
 class Sabeel < ApplicationRecord
+  # * Constants
+  APARTMENTS = %i[mohammedi taiyebi burhani maimoon_a maimoon_b]
+
+  # * Defaults
+  attribute :apartment, default: nil
+
   # * Associations
   has_many :thaalis, dependent: :destroy
   has_many :transactions, through: :thaalis
@@ -21,8 +27,10 @@ def sluggables = [its]
   include ITSValidation
   include NameValidation
 
+  using ArrayExtensions
+
   # * Enums
-  enum :apartment, APARTMENTS
+  enum apartment: APARTMENTS.to_h_titleize_value
 
   # * Scopes
   scope :no_thaali, -> { where.missing(:thaalis) }
diff --git a/app/models/thaali.rb b/app/models/thaali.rb
index 382512ec..85226369 100644
--- a/app/models/thaali.rb
+++ b/app/models/thaali.rb
@@ -1,6 +1,13 @@
 class Thaali < ApplicationRecord
+  # * Constants
+  SIZES = %i[small medium large]
+
   attr_readonly :total, :year
 
+  # * Defaults
+  attribute :year, default: CURR_YR
+  attribute :size, default: nil
+
   # * Associtions
   belongs_to :sabeel
   has_many :transactions, dependent: :destroy
@@ -16,8 +23,10 @@ class Thaali < ApplicationRecord
 
   def sluggables = [year, number]
 
+  using ArrayExtensions
+
   # * Enums
-  enum :size, SIZES
+  enum size: SIZES.to_h_titleize_value
 
   # * Scopes
   scope :dues_cleared_in, ->(year) {
diff --git a/app/models/transaction.rb b/app/models/transaction.rb
index 32ccdcd5..c20f5ef6 100644
--- a/app/models/transaction.rb
+++ b/app/models/transaction.rb
@@ -1,6 +1,12 @@
 class Transaction < ApplicationRecord
+  # * Constants
+  MODES = %i[cash cheque bank]
+
   default_scope { order(date: :desc) }
 
+  # * Defaults
+  attribute :mode, default: nil
+
   # * Associations
   belongs_to :thaali
 
@@ -16,8 +22,10 @@ class Transaction < ApplicationRecord
 
   def sluggables = [recipe_no]
 
+  using ArrayExtensions
+
   # * Enums
-  enum :mode, MODES
+  enum mode: MODES.to_h_titleize_value
 
   # * Scopes
   scope :that_occured_on, ->(date) { where(date: date) }
diff --git a/app/models/user.rb b/app/models/user.rb
index 08d8937a..1d65f77e 100644
--- a/app/models/user.rb
+++ b/app/models/user.rb
@@ -25,8 +25,6 @@ def is?(type) = role == type
 
   # * Custom Validations
   def must_have_a_role
-    unless roles.any?
-      errors.add(:role_ids, "selection is required")
-    end
+    errors.add(:role_ids, "selection is required") unless roles.any?
   end
 end
diff --git a/app/views/sabeels/_form.html.erb b/app/views/sabeels/_form.html.erb
index dc31b8e8..eadd65fd 100644
--- a/app/views/sabeels/_form.html.erb
+++ b/app/views/sabeels/_form.html.erb
@@ -3,7 +3,7 @@
     <%= f.error_notification %>
     <%= f.input :its %>
     <%= f.input :name, placeholder: "Juzer Shabbir Shakir" %>
-    <%= f.input :apartment, collection: APARTMENTS.map { [_1.to_s.titleize, _1] }, as: :radio_buttons %>
+    <%= f.input :apartment, collection: Sabeel.apartments.invert.to_a, as: :radio_buttons %>
     <%= f.input :flat_no %>
     <%= f.input :mobile, placeholder: "9876543210" %>
     <%= f.input :email %>
diff --git a/app/views/thaalis/_form.html.erb b/app/views/thaalis/_form.html.erb
index 4d0c494a..7fab3c2c 100644
--- a/app/views/thaalis/_form.html.erb
+++ b/app/views/thaalis/_form.html.erb
@@ -1,11 +1,10 @@
 <div class="container col-xxl-6 col-xl-7 col-lg-8 col-md-11 col-sm-10 pt-4 p-5 bg-white bg-opacity-50 shadow-lg border border-2 border-success-subtle rounded-4 mb-5">
-  <%= simple_form_for @thaali, url: url_helper do |f| %>
+  <%= simple_form_for @thaali, url: path do |f| %>
     <%= f.error_notification %>
 
-    <%# for new thaali it will show current year %>
-    <%= f.input :year, disabled: true, input_html: {value: (action_name == "edit") ? @thaali.year : CURR_YR} %>
+    <%= f.input :year, disabled: true %>
     <%= f.input :number %>
-    <%= f.input :size, collection: SIZES.map { [_1.capitalize, _1] }, as: :radio_buttons %>
+    <%= f.input :size, collection: Thaali.sizes.invert.to_a, as: :radio_buttons %>
     <%= f.input :total, disabled: action_name == "edit" %>
     <%= f.button :submit, action_name: %>
   <% end %>
diff --git a/app/views/thaalis/edit.html.erb b/app/views/thaalis/edit.html.erb
index 9565b1e1..55b6c767 100644
--- a/app/views/thaalis/edit.html.erb
+++ b/app/views/thaalis/edit.html.erb
@@ -2,4 +2,4 @@
 
 <h2 class="heading mb-3">Edit Thaali</h2>
 
-<%= render "form", url_helper: thaali_path %>
+<%= render "form", path: thaali_path %>
diff --git a/app/views/thaalis/new.html.erb b/app/views/thaalis/new.html.erb
index 9d93268d..80878996 100644
--- a/app/views/thaalis/new.html.erb
+++ b/app/views/thaalis/new.html.erb
@@ -2,4 +2,4 @@
 
 <h2 class="heading mb-3">New Thaali</h2>
 
-<%= render "form", url_helper: sabeel_thaalis_path %>
+<%= render "form", path: sabeel_thaalis_path %>
diff --git a/app/views/transactions/_form.html.erb b/app/views/transactions/_form.html.erb
index 61f4e72a..2c9c8518 100644
--- a/app/views/transactions/_form.html.erb
+++ b/app/views/transactions/_form.html.erb
@@ -3,7 +3,7 @@
     <%= f.error_notification %>
     <%= f.input :recipe_no %>
     <%= f.input :amount, hint: "Amount shouldn't be greater than: ₹#{total_balance}" %>
-    <%= f.input :mode, collection: MODES.map { [_1.capitalize, _1] }, as: :radio_buttons %>
+    <%= f.input :mode, collection: Transaction.modes.invert.to_a, as: :radio_buttons %>
     <%= f.input :date, order: %i[day month year] %>
     <%= f.button :submit, action_name: %>
   <% end %>
diff --git a/config/initializers/constant.rb b/config/initializers/constant.rb
index 7c264c93..a8bb467e 100644
--- a/config/initializers/constant.rb
+++ b/config/initializers/constant.rb
@@ -1,7 +1,2 @@
-# ! Add new apartments, sizes & modes to the END of the list
-APARTMENTS = %i[mohammedi taiyebi burhani maimoon_a maimoon_b]
-SIZES = %i[small medium large]
-MODES = %i[cash cheque bank]
-ROLES = %w[admin member viewer]
 CURR_YR = 2022
 PREV_YR = CURR_YR - 1
diff --git a/db/migrate/20231230113604_replace_apartment_integer_with_apartment_enum_type_in_sabeel.rb b/db/migrate/20231230113604_replace_apartment_integer_with_apartment_enum_type_in_sabeel.rb
new file mode 100644
index 00000000..c6240f53
--- /dev/null
+++ b/db/migrate/20231230113604_replace_apartment_integer_with_apartment_enum_type_in_sabeel.rb
@@ -0,0 +1,29 @@
+class ReplaceApartmentIntegerWithApartmentEnumTypeInSabeel < ActiveRecord::Migration[7.1]
+  def change
+    apartments = ["Mohammedi", "Taiyebi", "Burhani", "Maimoon A", "Maimoon B"]
+    create_enum :apartments, apartments
+
+    add_column :sabeels, :apartment_enum, :enum, enum_type: :apartments, default: "Mohammedi", null: false
+
+    reversible do |direction|
+      # rubocop:disable Rails/SkipsModelValidations
+      direction.up do
+        apartments.each_with_index do |apartment, i|
+          Sabeel.where(apartment: i).update_all(apartment_enum: apartment)
+        end
+      end
+
+      direction.down do
+        apartments.each_with_index do |apartment, i|
+          Sabeel.where(apartment_enum: apartment).update_all(apartment: i)
+        end
+        # to access `#apartment` data, update the enum value of it in `app/models/sabeels` file:
+        # enum apartment: APARTMENTS
+      end
+      # rubocop:enable Rails/SkipsModelValidations
+    end
+
+    remove_column :sabeels, :apartment, :integer
+    rename_column :sabeels, :apartment_enum, :apartment
+  end
+end
diff --git a/db/migrate/20231230135852_replace_size_integer_with_size_enum_type_in_thaali.rb b/db/migrate/20231230135852_replace_size_integer_with_size_enum_type_in_thaali.rb
new file mode 100644
index 00000000..cb6364a2
--- /dev/null
+++ b/db/migrate/20231230135852_replace_size_integer_with_size_enum_type_in_thaali.rb
@@ -0,0 +1,29 @@
+class ReplaceSizeIntegerWithSizeEnumTypeInThaali < ActiveRecord::Migration[7.1]
+  def change
+    sizes = %w[Small Medium Large]
+    create_enum :sizes, sizes
+
+    add_column :thaalis, :size_enum, :enum, enum_type: :sizes, default: "Small", null: false
+
+    reversible do |direction|
+      # rubocop:disable Rails/SkipsModelValidations
+      direction.up do
+        sizes.each_with_index do |size, i|
+          Thaali.where(size: i).update_all(size_enum: size)
+        end
+      end
+
+      direction.down do
+        sizes.each_with_index do |size, i|
+          Thaali.where(size_enum: size).update_all(size: i)
+        end
+        # to access `#size` data, update the enum value of it in `app/models/thaalis` file:
+        # enum size: SIZES
+      end
+      # rubocop:enable Rails/SkipsModelValidations
+    end
+
+    remove_column :thaalis, :size, :integer
+    rename_column :thaalis, :size_enum, :size
+  end
+end
diff --git a/db/migrate/20231230171413_replace_mode_integer_with_mode_enum_type_in_transaction.rb b/db/migrate/20231230171413_replace_mode_integer_with_mode_enum_type_in_transaction.rb
new file mode 100644
index 00000000..b4e43fbb
--- /dev/null
+++ b/db/migrate/20231230171413_replace_mode_integer_with_mode_enum_type_in_transaction.rb
@@ -0,0 +1,29 @@
+class ReplaceModeIntegerWithModeEnumTypeInTransaction < ActiveRecord::Migration[7.1]
+  def change
+    modes = %w[Cash Cheque Bank]
+    create_enum :modes, modes
+
+    add_column :transactions, :mode_enum, :enum, enum_type: :modes, default: "Cash", null: false
+
+    reversible do |direction|
+      # rubocop:disable Rails/SkipsModelValidations
+      direction.up do
+        modes.each_with_index do |mode, i|
+          Transaction.where(mode: i).update_all(mode_enum: mode)
+        end
+      end
+
+      direction.down do
+        modes.each_with_index do |mode, i|
+          Transaction.where(mode_enum: mode).update_all(mode: i)
+        end
+        # to access `#mode` data, update the enum value of it in `app/models/transactions` file:
+        # enum mode: MODES
+      end
+      # rubocop:enable Rails/SkipsModelValidations
+    end
+
+    remove_column :transactions, :mode, :integer
+    rename_column :transactions, :mode_enum, :mode
+  end
+end
diff --git a/db/schema.rb b/db/schema.rb
index 924009da..fa6df687 100644
--- a/db/schema.rb
+++ b/db/schema.rb
@@ -10,10 +10,16 @@
 #
 # It's strongly recommended that you check this file into your version control system.
 
-ActiveRecord::Schema[7.0].define(version: 2023_11_02_042517) do
+ActiveRecord::Schema[7.1].define(version: 2023_12_30_171413) do
   # These are extensions that must be enabled in order to support this database
   enable_extension "plpgsql"
 
+  # Custom types defined in this database.
+  # Note that some types may not work with other database engines. Be careful if changing database.
+  create_enum "apartments", ["Mohammedi", "Taiyebi", "Burhani", "Maimoon A", "Maimoon B"]
+  create_enum "modes", ["Cash", "Cheque", "Bank"]
+  create_enum "sizes", ["Small", "Medium", "Large"]
+
   create_table "friendly_id_slugs", force: :cascade do |t|
     t.string "slug", null: false
     t.integer "sluggable_id", null: false
@@ -38,13 +44,13 @@
   create_table "sabeels", force: :cascade do |t|
     t.integer "its", null: false
     t.string "name", null: false
-    t.integer "apartment", null: false
     t.integer "flat_no", null: false
     t.bigint "mobile", null: false
     t.string "email"
     t.string "slug", null: false
     t.datetime "created_at", null: false
     t.datetime "updated_at", null: false
+    t.enum "apartment", default: "Mohammedi", null: false, enum_type: "apartments"
     t.index ["its"], name: "index_sabeels_on_its", unique: true
     t.index ["slug"], name: "index_sabeels_on_slug", unique: true
   end
@@ -54,10 +60,10 @@
     t.integer "year", null: false
     t.integer "total", null: false
     t.integer "number", null: false
-    t.integer "size", null: false
     t.string "slug", null: false
     t.datetime "created_at", null: false
     t.datetime "updated_at", null: false
+    t.enum "size", default: "Small", null: false, enum_type: "sizes"
     t.index ["sabeel_id"], name: "index_thaalis_on_sabeel_id"
     t.index ["slug"], name: "index_thaalis_on_slug", unique: true
     t.index ["year", "sabeel_id"], name: "index_thaalis_on_year_and_sabeel_id", unique: true
@@ -66,12 +72,12 @@
   create_table "transactions", force: :cascade do |t|
     t.bigint "thaali_id", null: false
     t.integer "recipe_no", null: false
-    t.integer "mode", null: false
     t.integer "amount", null: false
     t.date "date", null: false
     t.string "slug", null: false
     t.datetime "created_at", null: false
     t.datetime "updated_at", null: false
+    t.enum "mode", default: "Cash", null: false, enum_type: "modes"
     t.index ["recipe_no"], name: "index_transactions_on_recipe_no", unique: true
     t.index ["slug"], name: "index_transactions_on_slug", unique: true
     t.index ["thaali_id"], name: "index_transactions_on_thaali_id"
diff --git a/db/seeds.rb b/db/seeds.rb
index 7f4bf252..df1756e8 100644
--- a/db/seeds.rb
+++ b/db/seeds.rb
@@ -5,10 +5,10 @@
   Sabeel.create(
     its: 10000000 + i,
     name: Faker::Name.name,
-    apartment: APARTMENTS.sample,
+    apartment: Sabeel::APARTMENTS.sample,
     flat_no: Faker::Number.within(range: 1..9999),
     mobile: Faker::Number.number(digits: 10),
-    email: Faker::Internet.free_email
+    email: Faker::Internet.email
   )
 end
 
@@ -20,7 +20,7 @@
     year: PREV_YR,
     total: 48000,
     number: i + 1,
-    size: SIZES.sample
+    size: Thaali::SIZES.sample
   )
 end
 
@@ -33,7 +33,7 @@
       amount: 4000,
       date: Faker::Date.in_date_period(year: PREV_YR),
       recipe_no: Random.rand(1..2000000),
-      mode: MODES.sample
+      mode: Transaction::MODES.sample
     )
   end
 end
@@ -48,7 +48,7 @@
       amount: 4000,
       date: Faker::Date.in_date_period(year: PREV_YR),
       recipe_no: Random.rand(2000001..3000000),
-      mode: MODES.sample
+      mode: Transaction::MODES.sample
     )
   end
 end
@@ -61,7 +61,7 @@
     year: CURR_YR,
     total: 60000,
     number: i + 1,
-    size: SIZES.sample
+    size: Thaali::SIZES.sample
   )
 end
 
@@ -75,7 +75,7 @@
         amount: 5000,
         date: Faker::Date.in_date_period(year: CURR_YR),
         recipe_no: Random.rand(3000001..6000000),
-        mode: MODES.sample
+        mode: Transaction::MODES.sample
       )
     end
   end
@@ -91,7 +91,7 @@
       amount: 5000,
       date: Faker::Date.in_date_period(year: CURR_YR),
       recipe_no: Random.rand(6000000..10000000),
-      mode: MODES.sample
+      mode: Transaction::MODES.sample
     )
   end
 end
@@ -100,9 +100,7 @@
 # *CREATES TOTAL Thaalis --> 175 (90 + 85)
 # *CREATES TOTAL Transactions --> ~1.1k
 
-ROLES.each do |role|
-  Role.create(name: role)
-end
+Role::NAMES.each { Role.create(name: _1) }
 
 User.create(
   its: 12345678,
diff --git a/spec/factories/roles.rb b/spec/factories/roles.rb
index 18174a4c..e04e648e 100644
--- a/spec/factories/roles.rb
+++ b/spec/factories/roles.rb
@@ -1,6 +1,6 @@
 FactoryBot.define do
   factory :role do
-    name { ROLES.sample }
+    name { Role::NAMES.sample }
 
     # * Factories
     factory :admin do
diff --git a/spec/factories/sabeels.rb b/spec/factories/sabeels.rb
index 0da1a891..6756dbda 100644
--- a/spec/factories/sabeels.rb
+++ b/spec/factories/sabeels.rb
@@ -2,7 +2,7 @@
 
 FactoryBot.define do
   factory :sabeel do
-    apartment { APARTMENTS.sample }
+    apartment { Sabeel::APARTMENTS.sample }
     email { Faker::Internet.email }
     flat_no { Faker::Number.within(range: 1..9999) }
     # rubocop:disable RSpec/NoExpectationExample
diff --git a/spec/factories/thaalis.rb b/spec/factories/thaalis.rb
index cd588a19..1c441236 100644
--- a/spec/factories/thaalis.rb
+++ b/spec/factories/thaalis.rb
@@ -4,7 +4,7 @@
   factory :thaali do
     sabeel
     number { Random.rand(1..10000) }
-    sequence :size, SIZES.cycle
+    sequence :size, Thaali::SIZES.cycle
     total { Faker::Number.number(digits: 5) }
     year { Random.rand(1..CURR_YR) }
 
diff --git a/spec/factories/transactions.rb b/spec/factories/transactions.rb
index d7582438..618a6845 100644
--- a/spec/factories/transactions.rb
+++ b/spec/factories/transactions.rb
@@ -6,7 +6,7 @@
     amount { Faker::Number.number(digits: 4) }
     date { Faker::Date.backward }
     recipe_no { Random.rand(1000..100000) }
-    sequence :mode, MODES.cycle
+    sequence :mode, Transaction::MODES.cycle
 
     factory :cleared_transaction, traits: [:cleared]
     factory :today_transaction, traits: [:today]
diff --git a/spec/features/sabeels/new_spec.rb b/spec/features/sabeels/new_spec.rb
index f066aa2f..c255fc4b 100644
--- a/spec/features/sabeels/new_spec.rb
+++ b/spec/features/sabeels/new_spec.rb
@@ -21,7 +21,7 @@
     it { expect(page).to have_title "New Sabeel" }
 
     context "with valid values" do
-      let(:apartment) { APARTMENTS.sample.to_s.titleize }
+      let(:apartment) { Sabeel.apartments.values.sample }
 
       before do
         choose apartment
diff --git a/spec/features/statistics/thaalis_spec.rb b/spec/features/statistics/thaalis_spec.rb
index f6112b3a..283bd381 100644
--- a/spec/features/statistics/thaalis_spec.rb
+++ b/spec/features/statistics/thaalis_spec.rb
@@ -47,7 +47,7 @@
 
     it "each size" do
       within("div##{CURR_YR}") do
-        SIZES.each { expect(page).to have_content("#{_1.capitalize}: #{thaalis.send(_1).count}") }
+        Thaali::SIZES.each { |k, v| expect(page).to have_content("#{v}: #{thaalis.send(k).count}") }
       end
     end
 
diff --git a/spec/features/thaalis/new_spec.rb b/spec/features/thaalis/new_spec.rb
index fad27836..773742fe 100644
--- a/spec/features/thaalis/new_spec.rb
+++ b/spec/features/thaalis/new_spec.rb
@@ -47,7 +47,7 @@
 
       context "with valid values" do
         before do
-          choose thaali[:size].capitalize
+          choose thaali[:size].to_s.titleize
           click_button "Create Thaali"
         end
 
diff --git a/spec/features/transactions/new_spec.rb b/spec/features/transactions/new_spec.rb
index 52aefde3..7f37fcda 100644
--- a/spec/features/transactions/new_spec.rb
+++ b/spec/features/transactions/new_spec.rb
@@ -22,9 +22,10 @@
 
     context "with valid values" do
       let(:new_transaction) { Transaction.last }
+      let(:mode) { Transaction.modes.values.sample }
 
       before do
-        choose MODES.sample.capitalize
+        choose mode
         click_button "Create Transaction"
       end
 
diff --git a/spec/features/users/new_spec.rb b/spec/features/users/new_spec.rb
index 5eafc564..da10969b 100644
--- a/spec/features/users/new_spec.rb
+++ b/spec/features/users/new_spec.rb
@@ -20,7 +20,7 @@
 
       attributes_for(:user).each do |k, v|
         case k
-        when :roles then choose ROLES.sample.capitalize
+        when :roles then choose Role::NAMES.sample.titleize
         else fill_in "user_#{k}", with: v
         end
       end
diff --git a/spec/models/role_spec.rb b/spec/models/role_spec.rb
index 0422e381..eba04d5d 100644
--- a/spec/models/role_spec.rb
+++ b/spec/models/role_spec.rb
@@ -9,7 +9,7 @@
     context "with name" do
       it { is_expected.to validate_presence_of(:name).with_message("selection is required") }
 
-      it { is_expected.to validate_inclusion_of(:name).in_array(ROLES) }
+      it { is_expected.to validate_inclusion_of(:name).in_array(Role::NAMES) }
     end
   end
 end
diff --git a/spec/models/sabeel_spec.rb b/spec/models/sabeel_spec.rb
index e8c5b9fa..b7257fd0 100644
--- a/spec/models/sabeel_spec.rb
+++ b/spec/models/sabeel_spec.rb
@@ -11,6 +11,12 @@
     it { is_expected.to have_many(:transactions).through(:thaalis) }
   end
 
+  context "with attributes" do
+    describe "set default values of" do
+      it { expect(described_class.new.apartment).to be_nil }
+    end
+  end
+
   context "when validating" do
     context "with email" do
       it { is_expected.to validate_email_format_of(:email) }
@@ -18,11 +24,9 @@
     end
 
     context "with apartment" do
-      let(:all_apartments) { described_class.apartments.keys }
-
       it { is_expected.to validate_presence_of(:apartment).with_message("selection is required") }
 
-      it { is_expected.to define_enum_for(:apartment).with_values(all_apartments) }
+      it { is_expected.to define_enum_for(:apartment).with_values(described_class::APARTMENTS.to_h { [_1, _1.to_s.titleize] }).backed_by_column_of_type(:enum) }
     end
 
     context "with flat_no" do
diff --git a/spec/models/thaali_spec.rb b/spec/models/thaali_spec.rb
index d6a5f07a..1bc65883 100644
--- a/spec/models/thaali_spec.rb
+++ b/spec/models/thaali_spec.rb
@@ -13,6 +13,11 @@
   context "with attributes" do
     it { is_expected.to have_readonly_attribute(:year) }
     it { is_expected.to have_readonly_attribute(:total) }
+
+    describe "set default values of" do
+      it { expect(described_class.new.year).to eq(CURR_YR) }
+      it { expect(described_class.new.size).to be_nil }
+    end
   end
 
   context "when validating" do
@@ -22,7 +27,7 @@
     end
 
     context "with size" do
-      it { is_expected.to define_enum_for(:size).with_values([:small, :medium, :large]) }
+      it { is_expected.to define_enum_for(:size).with_values(described_class::SIZES.to_h { [_1, _1.to_s.titleize] }).backed_by_column_of_type(:enum) }
       it { is_expected.to validate_presence_of(:size).with_message("selection is required") }
     end
 
diff --git a/spec/models/transaction_spec.rb b/spec/models/transaction_spec.rb
index 78b194e6..6fe779df 100644
--- a/spec/models/transaction_spec.rb
+++ b/spec/models/transaction_spec.rb
@@ -11,12 +11,17 @@
     it { is_expected.to belong_to(:thaali) }
   end
 
+  context "with attributes" do
+    describe "set default values of" do
+      it { expect(described_class.new.mode).to be_nil }
+    end
+  end
+
   context "when validating" do
     context "with mode" do
-      let(:mode_of_payments) { %i[cash cheque bank] }
-
       it { is_expected.to validate_presence_of(:mode).with_message("selection is required") }
-      it { is_expected.to define_enum_for(:mode).with_values(mode_of_payments) }
+
+      it { is_expected.to define_enum_for(:mode).with_values(described_class::MODES.to_h { [_1, _1.to_s.titleize] }).backed_by_column_of_type(:enum) }
     end
 
     context "with amount" do
diff --git a/spec/requests/sabeels/active_spec.rb b/spec/requests/sabeels/active_spec.rb
index 96139f7c..af2666a2 100644
--- a/spec/requests/sabeels/active_spec.rb
+++ b/spec/requests/sabeels/active_spec.rb
@@ -3,7 +3,7 @@
 require "rails_helper"
 
 RSpec.describe "Thaali Active request" do
-  let(:apartment) { APARTMENTS.sample }
+  let(:apartment) { Sabeel::APARTMENTS.sample }
 
   # * NOT ACCESSIBLE
   context "when made by logged out user" do
diff --git a/spec/requests/sabeels/inactive_spec.rb b/spec/requests/sabeels/inactive_spec.rb
index a2d526a2..bbac8579 100644
--- a/spec/requests/sabeels/inactive_spec.rb
+++ b/spec/requests/sabeels/inactive_spec.rb
@@ -3,7 +3,7 @@
 require "rails_helper"
 
 RSpec.describe "Thaali Inactive request" do
-  let(:apartment) { APARTMENTS.sample }
+  let(:apartment) { Sabeel::APARTMENTS.sample }
 
   # * NOT ACCESSIBLE
   context "when made by logged out user" do