aasm_example.rb

base.send :include, AASM
base.aasm_column :status

base.aasm_initial_state :drafted

base.aasm_state :drafted
base.aasm_state :submitted
base.aasm_state :booked
base.aasm_state :lost
base.aasm_state :cancelled

base.aasm_event :submit do
  transitions :to => :submitted, :from => [:drafted, :lost], :on_transition => lambda {|quote| quote.cache_project_total }
end

acts_as_state_machine_example.rb

base.acts_as_state_machine :initial => :not_started

base.state :not_started
base.state :working
base.state :pending_approval
base.state :approved, :enter => lambda { |order| OrderMailer::deliver_order_approved_notice(order) }
base.state :submitted
base.state :disapproved

base.event :submit_order_for_approval do
  transitions :from => :working, :to => :approved
end