diff --git a/src/HealthGPS.Console/configuration.cpp b/src/HealthGPS.Console/configuration.cpp
index ce90ded79..85f30a841 100644
--- a/src/HealthGPS.Console/configuration.cpp
+++ b/src/HealthGPS.Console/configuration.cpp
@@ -338,7 +338,7 @@ ModelInput create_model_input(core::DataTable &input_table, core::Country countr
         if (item.range.empty()) {
             mapping.emplace_back(item.name, item.level);
         } else {
-            auto boundary = FactorRange{item.range[0], item.range[1]};
+            auto boundary = hgps::OptionalRange{{item.range[0], item.range[1]}};
             mapping.emplace_back(item.name, item.level, boundary);
         }
     }
diff --git a/src/HealthGPS/mapping.cpp b/src/HealthGPS/mapping.cpp
index faf004a8f..171404782 100644
--- a/src/HealthGPS/mapping.cpp
+++ b/src/HealthGPS/mapping.cpp
@@ -8,8 +8,8 @@
 
 namespace hgps {
 
-MappingEntry::MappingEntry(std::string name, int level, FactorRange range)
-    : name_{std::move(name)}, name_key_{name_}, level_{level}, range_{range} {}
+MappingEntry::MappingEntry(std::string name, int level, OptionalRange range)
+    : name_{std::move(name)}, name_key_{name_}, level_{level}, range_{std::move(range)} {}
 
 const std::string &MappingEntry::name() const noexcept { return name_; }
 
@@ -17,14 +17,13 @@ int MappingEntry::level() const noexcept { return level_; }
 
 const core::Identifier &MappingEntry::key() const noexcept { return name_key_; }
 
-const FactorRange &MappingEntry::range() const noexcept { return range_; }
+const OptionalRange &MappingEntry::range() const noexcept { return range_; }
 
 double MappingEntry::get_bounded_value(const double &value) const noexcept {
-    if (range_.empty) {
-        return value;
+    if (range_.has_value()) {
+        return std::min(std::max(value, range_->first), range_->second);
     }
-
-    return std::min(std::max(value, range_.minimum), range_.maximum);
+    return value;
 }
 
 inline bool operator>(const MappingEntry &lhs, const MappingEntry &rhs) {
@@ -74,4 +73,4 @@ std::vector<MappingEntry> HierarchicalMapping::at_level(int level) const noexcep
     return result;
 }
 
-} // namespace hgps
\ No newline at end of file
+} // namespace hgps
diff --git a/src/HealthGPS/mapping.h b/src/HealthGPS/mapping.h
index b8877536b..8ee51ff76 100644
--- a/src/HealthGPS/mapping.h
+++ b/src/HealthGPS/mapping.h
@@ -11,34 +11,8 @@ namespace hgps {
 /// @brief The constant in the regression model presentation identifier
 inline const core::Identifier InterceptKey = core::Identifier{"intercept"};
 
-/// @brief Defines the risk factor allowed range data type
-///
-/// @details The factors range is defined from the fitted dataset and enforced
-/// by the simulation algorithm. The default constructor, creates an empty range.
-struct FactorRange {
-    /// @brief Initialises a new instance of the FactorRange structure
-    FactorRange() = default;
-
-    /// @brief Initialises a new instance of the FactorRange structure
-    /// @param min_value Minimum factor value
-    /// @param max_value Maximum factor value
-    /// @throws std::invalid_argument for minimum greater than the maximum value
-    FactorRange(double min_value, double max_value)
-        : empty{false}, minimum{min_value}, maximum{max_value} {
-        if (min_value > max_value) {
-            throw std::invalid_argument("Factor range minimum must not be greater than maximum.");
-        }
-    }
-
-    /// @brief Gets a value indicating whether the range is empty, no limits.
-    bool empty{true};
-
-    /// @brief The range minimum value
-    double minimum{};
-
-    /// @brief The range maximum value
-    double maximum{};
-};
+/// @brief Optional Range of doubles data type
+using OptionalRange = std::optional<std::pair<double, double>>;
 
 /// @brief Defines risk factor mapping entry data type
 ///
@@ -52,7 +26,7 @@ class MappingEntry {
     /// @param name Risk factor name
     /// @param level The hierarchical level
     /// @param range The factor range
-    MappingEntry(std::string name, int level, FactorRange range = {});
+    MappingEntry(std::string name, int level, OptionalRange range = {});
 
     /// @brief Gets the factor name
     /// @return Factor name
@@ -68,7 +42,7 @@ class MappingEntry {
 
     /// @brief Gets the factor allowed values range
     /// @return Factor values range
-    const FactorRange &range() const noexcept;
+    const OptionalRange &range() const noexcept;
 
     /// @brief Adjusts a value to the factor range, if provided
     /// @param value The value to adjust
@@ -79,7 +53,7 @@ class MappingEntry {
     std::string name_;
     core::Identifier name_key_;
     int level_{};
-    FactorRange range_;
+    OptionalRange range_;
 };
 
 /// @brief Defines the hierarchical model mapping data type
@@ -147,4 +121,4 @@ class HierarchicalMapping {
     std::vector<MappingEntry> mapping_;
 };
 
-} // namespace hgps
\ No newline at end of file
+} // namespace hgps