quality_calculator.rb

class QualityCalculator
  def self.calculate_for_normal_award(award)
    # normal award logic here
    # which would update the quality of the award passed in
    return award
  end
  
  def self.calculate_for_blue_first_award(award)
    # blue first award logic here
    # which would update the quality of the award passed in
    return award
  end
  
  def self.calculate_for_blue_distinction_award(award)
    # blue distinction award logic here
    # which would update the quality of the award passed in
    return award
  end
  
  def self.calculate(award)
    return QualityCalculator.calculate_for_blue_distinction_award(award) if award.name == 'Blue Distinction'
    return QualityCalculator.calculate_for_blue_first_award(award) if award.name == 'Blue First'
    QualityCalculator.calculate_for_normal_award(award)
  end
end

# then you can use it in update_quality method
def update_quality(awards)
  awards.each { |award| QualityCalculator.calculate(award) }
end