diff --git a/test/yulPhaser/Phaser.cpp b/test/yulPhaser/Phaser.cpp
index ea06dd771..aab34db61 100644
--- a/test/yulPhaser/Phaser.cpp
+++ b/test/yulPhaser/Phaser.cpp
@@ -70,6 +70,7 @@ protected:
 	};
 	FitnessMetricFactory::Options m_options = {
 		/* metric = */ MetricChoice::CodeSize,
+		/* metricAggregator = */ MetricAggregatorChoice::Average,
 		/* relativeMetricScale = */ 5,
 		/* chromosomeRepetitions = */ 1,
 	};
@@ -152,15 +153,16 @@ BOOST_AUTO_TEST_SUITE(FitnessMetricFactoryTest)
 BOOST_FIXTURE_TEST_CASE(build_should_create_metric_of_the_right_type, FitnessMetricFactoryFixture)
 {
 	m_options.metric = MetricChoice::RelativeCodeSize;
+	m_options.metricAggregator = MetricAggregatorChoice::Sum;
 	unique_ptr<FitnessMetric> metric = FitnessMetricFactory::build(m_options, {m_programs[0]});
 	BOOST_REQUIRE(metric != nullptr);
 
-	auto averageMetric = dynamic_cast<FitnessMetricAverage*>(metric.get());
-	BOOST_REQUIRE(averageMetric != nullptr);
-	BOOST_REQUIRE(averageMetric->metrics().size() == 1);
-	BOOST_REQUIRE(averageMetric->metrics()[0] != nullptr);
+	auto sumMetric = dynamic_cast<FitnessMetricSum*>(metric.get());
+	BOOST_REQUIRE(sumMetric != nullptr);
+	BOOST_REQUIRE(sumMetric->metrics().size() == 1);
+	BOOST_REQUIRE(sumMetric->metrics()[0] != nullptr);
 
-	auto relativeProgramSizeMetric = dynamic_cast<RelativeProgramSize*>(averageMetric->metrics()[0].get());
+	auto relativeProgramSizeMetric = dynamic_cast<RelativeProgramSize*>(sumMetric->metrics()[0].get());
 	BOOST_REQUIRE(relativeProgramSizeMetric != nullptr);
 	BOOST_TEST(toString(relativeProgramSizeMetric->program()) == toString(m_programs[0]));
 }
@@ -168,6 +170,7 @@ BOOST_FIXTURE_TEST_CASE(build_should_create_metric_of_the_right_type, FitnessMet
 BOOST_FIXTURE_TEST_CASE(build_should_respect_chromosome_repetitions_option, FitnessMetricFactoryFixture)
 {
 	m_options.metric = MetricChoice::CodeSize;
+	m_options.metricAggregator = MetricAggregatorChoice::Average;
 	m_options.chromosomeRepetitions = 5;
 	unique_ptr<FitnessMetric> metric = FitnessMetricFactory::build(m_options, {m_programs[0]});
 	BOOST_REQUIRE(metric != nullptr);
@@ -185,6 +188,7 @@ BOOST_FIXTURE_TEST_CASE(build_should_respect_chromosome_repetitions_option, Fitn
 BOOST_FIXTURE_TEST_CASE(build_should_set_relative_metric_scale, FitnessMetricFactoryFixture)
 {
 	m_options.metric = MetricChoice::RelativeCodeSize;
+	m_options.metricAggregator = MetricAggregatorChoice::Average;
 	m_options.relativeMetricScale = 10;
 	unique_ptr<FitnessMetric> metric = FitnessMetricFactory::build(m_options, {m_programs[0]});
 	BOOST_REQUIRE(metric != nullptr);
diff --git a/tools/yulPhaser/Phaser.cpp b/tools/yulPhaser/Phaser.cpp
index d0d9d9a1e..c62b62dc3 100644
--- a/tools/yulPhaser/Phaser.cpp
+++ b/tools/yulPhaser/Phaser.cpp
@@ -60,12 +60,23 @@ map<MetricChoice, string> MetricChoiceToStringMap =
 };
 map<string, MetricChoice> const StringToMetricChoiceMap = invertMap(MetricChoiceToStringMap);
 
+map<MetricAggregatorChoice, string> const MetricAggregatorChoiceToStringMap =
+{
+	{MetricAggregatorChoice::Average, "average"},
+	{MetricAggregatorChoice::Sum, "sum"},
+	{MetricAggregatorChoice::Maximum, "maximum"},
+	{MetricAggregatorChoice::Minimum, "minimum"},
+};
+map<string, MetricAggregatorChoice> const StringToMetricAggregatorChoiceMap = invertMap(MetricAggregatorChoiceToStringMap);
+
 }
 
 istream& phaser::operator>>(istream& _inputStream, Algorithm& _algorithm) { return deserializeChoice(_inputStream, _algorithm, StringToAlgorithmMap); }
 ostream& phaser::operator<<(ostream& _outputStream, Algorithm _algorithm) { return serializeChoice(_outputStream, _algorithm, AlgorithmToStringMap); }
 istream& phaser::operator>>(istream& _inputStream, MetricChoice& _metric) { return deserializeChoice(_inputStream, _metric, StringToMetricChoiceMap); }
 ostream& phaser::operator<<(ostream& _outputStream, MetricChoice _metric) { return serializeChoice(_outputStream, _metric, MetricChoiceToStringMap); }
+istream& phaser::operator>>(istream& _inputStream, MetricAggregatorChoice& _aggregator) { return deserializeChoice(_inputStream, _aggregator, StringToMetricAggregatorChoiceMap); }
+ostream& phaser::operator<<(ostream& _outputStream, MetricAggregatorChoice _aggregator) { return serializeChoice(_outputStream, _aggregator, MetricAggregatorChoiceToStringMap); }
 
 GeneticAlgorithmFactory::Options GeneticAlgorithmFactory::Options::fromCommandLine(po::variables_map const& _arguments)
 {
@@ -139,6 +150,7 @@ FitnessMetricFactory::Options FitnessMetricFactory::Options::fromCommandLine(po:
 {
 	return {
 		_arguments["metric"].as<MetricChoice>(),
+		_arguments["metric-aggregator"].as<MetricAggregatorChoice>(),
 		_arguments["relative-metric-scale"].as<size_t>(),
 		_arguments["chromosome-repetitions"].as<size_t>(),
 	};
@@ -178,7 +190,19 @@ unique_ptr<FitnessMetric> FitnessMetricFactory::build(
 			assertThrow(false, solidity::util::Exception, "Invalid MetricChoice value.");
 	}
 
-	return make_unique<FitnessMetricAverage>(move(metrics));
+	switch (_options.metricAggregator)
+	{
+		case MetricAggregatorChoice::Average:
+			return make_unique<FitnessMetricAverage>(move(metrics));
+		case MetricAggregatorChoice::Sum:
+			return make_unique<FitnessMetricSum>(move(metrics));
+		case MetricAggregatorChoice::Maximum:
+			return make_unique<FitnessMetricMaximum>(move(metrics));
+		case MetricAggregatorChoice::Minimum:
+			return make_unique<FitnessMetricMinimum>(move(metrics));
+		default:
+			assertThrow(false, solidity::util::Exception, "Invalid MetricAggregatorChoice value.");
+	}
 }
 
 PopulationFactory::Options PopulationFactory::Options::fromCommandLine(po::variables_map const& _arguments)
@@ -442,6 +466,12 @@ Phaser::CommandLineDescription Phaser::buildCommandLineDescription()
 			po::value<MetricChoice>()->value_name("<NAME>")->default_value(MetricChoice::CodeSize),
 			"Metric used to evaluate the fitness of a chromosome."
 		)
+		(
+			"metric-aggregator",
+			po::value<MetricAggregatorChoice>()->value_name("<NAME>")->default_value(MetricAggregatorChoice::Average),
+			"Operator used to combine multiple fitness metric obtained by evaluating a chromosome "
+			"separately for each input program."
+		)
 		(
 			"relative-metric-scale",
 			po::value<size_t>()->value_name("<EXPONENT>")->default_value(3),
diff --git a/tools/yulPhaser/Phaser.h b/tools/yulPhaser/Phaser.h
index 55c808f07..2e72c31f6 100644
--- a/tools/yulPhaser/Phaser.h
+++ b/tools/yulPhaser/Phaser.h
@@ -58,10 +58,20 @@ enum class MetricChoice
 	RelativeCodeSize,
 };
 
+enum class MetricAggregatorChoice
+{
+	Average,
+	Sum,
+	Maximum,
+	Minimum,
+};
+
 std::istream& operator>>(std::istream& _inputStream, solidity::phaser::Algorithm& _algorithm);
 std::ostream& operator<<(std::ostream& _outputStream, solidity::phaser::Algorithm _algorithm);
 std::istream& operator>>(std::istream& _inputStream, solidity::phaser::MetricChoice& _metric);
 std::ostream& operator<<(std::ostream& _outputStream, solidity::phaser::MetricChoice _metric);
+std::istream& operator>>(std::istream& _inputStream, solidity::phaser::MetricAggregatorChoice& _aggregator);
+std::ostream& operator<<(std::ostream& _outputStream, solidity::phaser::MetricAggregatorChoice _aggregator);
 
 /**
  * Builds and validates instances of @a GeneticAlgorithm and its derived classes.
@@ -100,6 +110,7 @@ public:
 	struct Options
 	{
 		MetricChoice metric;
+		MetricAggregatorChoice metricAggregator;
 		size_t relativeMetricScale;
 		size_t chromosomeRepetitions;