diff --git a/check/check.go b/check/check.go
index 74c1182..8fe4f1a 100644
--- a/check/check.go
+++ b/check/check.go
@@ -11,6 +11,7 @@ import (
 	"github.com/nextmv-io/nextroute"
 	"github.com/nextmv-io/nextroute/check/schema"
 	"github.com/nextmv-io/nextroute/common"
+	"github.com/nextmv-io/sdk/run/statistics"
 )
 
 // ModelCheck is the check of a model returning a [Output].
@@ -222,7 +223,7 @@ SolutionPlanUnitLoop:
 					*m.output.PlanUnits[solutionPlanUnitIdx].VehiclesHaveMoves++
 				}
 
-				value := bestMove.Value()
+				value := statistics.Float64(bestMove.Value())
 				vehicleDetails := &schema.VehiclesWithMovesDetail{
 					VehicleID:              solutionVehicle.ModelVehicle().ID(),
 					DeltaObjectiveEstimate: &value,
@@ -268,7 +269,7 @@ SolutionPlanUnitLoop:
 					if planned {
 						moveIsImprovement = true
 						vehicleDetails.WasPlannable = true
-						deltaObjective := m.solution.Score() - actualScoreBeforeMove
+						deltaObjective := statistics.Float64(m.solution.Score() - actualScoreBeforeMove)
 						vehicleDetails.DeltaObjective = &deltaObjective
 
 						m.output.PlanUnits[solutionPlanUnitIdx].HasPlannableBestMove = true
diff --git a/check/schema/schema.go b/check/schema/schema.go
index b875816..7d74fb8 100644
--- a/check/schema/schema.go
+++ b/check/schema/schema.go
@@ -3,6 +3,8 @@
 // Package schema contains the core schemas for nextroute.
 package schema
 
+import "github.com/nextmv-io/sdk/run/statistics"
+
 // Output is the output of the  check.
 type Output struct {
 	// Error is the error raised during the check.
@@ -119,10 +121,10 @@ type VehiclesWithMovesDetail struct {
 	VehicleID string `json:"vehicle_id"`
 	// DeltaObjectiveEstimate is the estimate of the delta of the objective of
 	// that will be incurred by the move.
-	DeltaObjectiveEstimate *float64 `json:"delta_objective_estimate,omitempty"`
+	DeltaObjectiveEstimate *statistics.Float64 `json:"delta_objective_estimate,omitempty"`
 	// DeltaObjective is the actual delta of the objective of that will be
 	// incurred by the move.
-	DeltaObjective *float64 `json:"delta_objective,omitempty"`
+	DeltaObjective *statistics.Float64 `json:"delta_objective,omitempty"`
 	// FailedConstraints are the constraints that are violated for the move.
 	FailedConstraints []string `json:"failed_constraints,omitempty"`
 	// WasPlannable is true if the move was plannable, false otherwise.
diff --git a/factory/vehicles.go b/factory/vehicles.go
index be98a02..5cf18c0 100644
--- a/factory/vehicles.go
+++ b/factory/vehicles.go
@@ -3,7 +3,6 @@
 package factory
 
 import (
-	"encoding/json"
 	"errors"
 	"fmt"
 
@@ -45,16 +44,11 @@ func addVehicles(
 			}
 		}
 	case map[string]any:
-		var durationMatrices schema.TimeDependentMatrix
-		jsonData, err := json.Marshal(matrix)
+		timeDependentMatrix, err := convertToTimeDependentMatrix(matrix)
 		if err != nil {
 			return nil, err
 		}
-		err = json.Unmarshal(jsonData, &durationMatrices)
-		if err != nil {
-			return nil, err
-		}
-		travelDuration, err = dependentTravelDurationExpression(durationMatrices, model)
+		travelDuration, err = dependentTravelDurationExpression(timeDependentMatrix, model)
 		if err != nil {
 			return nil, err
 		}
@@ -64,16 +58,11 @@ func addVehicles(
 			travelDuration = travelDurationExpression(floatMatrix)
 		} else {
 			// If it's not [][]float64, try to assert it as []schema.DurationMatrices
-			var durationMatrices []schema.TimeDependentMatrix
-			jsonData, err := json.Marshal(matrix)
-			if err != nil {
-				return nil, err
-			}
-			err = json.Unmarshal(jsonData, &durationMatrices)
+			timeDependentMatrices, err := convertToTimeDependentMatrices(matrix)
 			if err != nil {
 				return nil, err
 			}
-			for _, durationMatrix := range durationMatrices {
+			for _, durationMatrix := range timeDependentMatrices {
 				m, err := dependentTravelDurationExpression(durationMatrix, model)
 				if err != nil {
 					return nil, err
diff --git a/go.mod b/go.mod
index 27c1c95..556a09d 100644
--- a/go.mod
+++ b/go.mod
@@ -3,7 +3,7 @@ module github.com/nextmv-io/nextroute
 go 1.21
 
 require (
-	github.com/nextmv-io/sdk v1.8.0
+	github.com/nextmv-io/sdk v1.8.1
 	gonum.org/v1/gonum v0.14.0
 )
 
diff --git a/go.sum b/go.sum
index d7b2267..029c8a1 100644
--- a/go.sum
+++ b/go.sum
@@ -301,8 +301,8 @@ github.com/modern-go/reflect2 v0.0.0-20180701023420-4b7aa43c6742/go.mod h1:bx2lN
 github.com/modern-go/reflect2 v1.0.1/go.mod h1:bx2lNnkwVCuqBIxFjflWJWanXIb3RllmbCylyMrvgv0=
 github.com/modern-go/reflect2 v1.0.2/go.mod h1:yWuevngMOJpCy52FWWMvUC8ws7m/LJsjYzDa0/r8luk=
 github.com/mwitkow/go-conntrack v0.0.0-20161129095857-cc309e4a2223/go.mod h1:qRWi+5nqEBWmkhHvq77mSJWrCKwh8bxhgT7d/eI7P4U=
-github.com/nextmv-io/sdk v1.8.0 h1:EqYibIyeaFRc9zgyPUUwbD2nx9z37l18YfJfVe1wHCU=
-github.com/nextmv-io/sdk v1.8.0/go.mod h1:Y48XLPcIOOxRgO86ICNpqGrH2N5+dd1TDNvef/FD2Kc=
+github.com/nextmv-io/sdk v1.8.1 h1:CYhhDtd4ZeFYfHXSinVQpvH4mIPJHOqtQGUaSwBfpp8=
+github.com/nextmv-io/sdk v1.8.1/go.mod h1:Y48XLPcIOOxRgO86ICNpqGrH2N5+dd1TDNvef/FD2Kc=
 github.com/opentracing/opentracing-go v1.2.0/go.mod h1:GxEUsuufX4nBwe+T+Wl9TAgYrxe9dPLANfrWvHYVTgc=
 github.com/pascaldekloe/goe v0.0.0-20180627143212-57f6aae5913c/go.mod h1:lzWF7FIEvWOWxwDKqyGYQf6ZUaNfKdP144TG7ZOy1lc=
 github.com/pascaldekloe/goe v0.1.0/go.mod h1:lzWF7FIEvWOWxwDKqyGYQf6ZUaNfKdP144TG7ZOy1lc=