diff --git a/org.emoflon.ilp/src/org/emoflon/ilp/Constant.java b/org.emoflon.ilp/src/org/emoflon/ilp/Constant.java
index 25848d0..6e9d6de 100644
--- a/org.emoflon.ilp/src/org/emoflon/ilp/Constant.java
+++ b/org.emoflon.ilp/src/org/emoflon/ilp/Constant.java
@@ -2,8 +2,7 @@
 
 /**
  * Record class representing constant values.
- *
  */
 public record Constant(double weight) {
 
-}
\ No newline at end of file
+}
diff --git a/org.emoflon.ilp/src/org/emoflon/ilp/Constraint.java b/org.emoflon.ilp/src/org/emoflon/ilp/Constraint.java
index 686ac41..80362dd 100644
--- a/org.emoflon.ilp/src/org/emoflon/ilp/Constraint.java
+++ b/org.emoflon.ilp/src/org/emoflon/ilp/Constraint.java
@@ -1,5 +1,30 @@
 package org.emoflon.ilp;
 
-public interface Constraint {
-	// empty
+/**
+ * Abstract class for all constraints.
+ */
+public abstract class Constraint {
+	/**
+	 * The name of the constraint.
+	 */
+	private String name;
+
+	/**
+	 * Returns the name of the constraint.
+	 * 
+	 * @return Name of the constraint.
+	 */
+	public String getName() {
+		return name;
+	}
+
+	/**
+	 * Sets the name of the constraint to a given value.
+	 * 
+	 * @param name New name of the constraint to set.
+	 */
+	public void setName(final String name) {
+		this.name = name;
+	}
+
 }
diff --git a/org.emoflon.ilp/src/org/emoflon/ilp/CplexSolver.java b/org.emoflon.ilp/src/org/emoflon/ilp/CplexSolver.java
index 30293c9..b0a0c9c 100644
--- a/org.emoflon.ilp/src/org/emoflon/ilp/CplexSolver.java
+++ b/org.emoflon.ilp/src/org/emoflon/ilp/CplexSolver.java
@@ -50,28 +50,28 @@ private void init() {
 
 			// set configuration parameters
 			// Presolve?
-			cplex.setParam(IloCplex.Param.Preprocessing.Presolve, config.presolveEnabled());
+			cplex.setParam(IloCplex.Param.Preprocessing.Presolve, config.isPresolveEnabled());
 			// Random Seed?
-			if (config.randomSeedEnabled()) {
-				cplex.setParam(IloCplex.Param.RandomSeed, config.randomSeed());
+			if (config.isRandomSeedEnabled()) {
+				cplex.setParam(IloCplex.Param.RandomSeed, config.getRandomSeed());
 			}
 			// Output?
-			if (!config.debugOutputEnabled()) {
+			if (!config.isDebugOutputEnabled()) {
 				cplex.setOut(null);
 			}
 			// Tolerance?
-			if (config.toleranceEnabled()) {
-				cplex.setParam(IloCplex.Param.MIP.Tolerances.Integrality, config.tolerance());
-				cplex.setParam(IloCplex.Param.MIP.Tolerances.AbsMIPGap, config.tolerance());
+			if (config.isToleranceEnabled()) {
+				cplex.setParam(IloCplex.Param.MIP.Tolerances.Integrality, config.getTolerance());
+				cplex.setParam(IloCplex.Param.MIP.Tolerances.AbsMIPGap, config.getTolerance());
 			}
 			// Timeout?
-			if (config.timeoutEnabled()) {
-				cplex.setParam(IloCplex.Param.TimeLimit, config.timeout());
+			if (config.isTimeoutEnabled()) {
+				cplex.setParam(IloCplex.Param.TimeLimit, config.getTimeout());
 			}
 
 			// set output path, if configured
-			if (config.outputEnabled()) {
-				this.outputPath = config.outputPath();
+			if (config.isOutputEnabled()) {
+				this.outputPath = config.getOutputPath();
 			}
 		} catch (final IloException e) {
 			throw new RuntimeException(e);
@@ -84,6 +84,7 @@ private void init() {
 	@Override
 	public void buildILPProblem(Problem problem) {
 		this.problem = problem;
+		problem.validateConstraints();
 
 		/*
 		 * // Quadratic Constraints or Functions are not yet implemented if
@@ -183,13 +184,13 @@ private IloIntVar translateIntegerVariable(IntegerVariable integerVariable) {
 			int lb = integerVariable.getLowerBound();
 			int ub = integerVariable.getUpperBound();
 
-			if (config.boundsEnabled()) {
+			if (config.isBoundsEnabled()) {
 				if (integerVariable.isDefaultLowerBound()) {
-					lb = config.lowerBound();
+					lb = config.getLowerBound();
 					integerVariable.setLowerBound((int) lb);
 				}
 				if (integerVariable.isDefaultUpperBound()) {
-					ub = config.upperBound();
+					ub = config.getUpperBound();
 					integerVariable.setUpperBound((int) ub);
 				}
 			}
@@ -216,13 +217,13 @@ private IloNumVar translateRealVariable(RealVariable realVariable) {
 			double lb = realVariable.getLowerBound();
 			double ub = realVariable.getUpperBound();
 
-			if (config.boundsEnabled()) {
+			if (config.isBoundsEnabled()) {
 				if (realVariable.isDefaultLowerBound()) {
-					lb = config.lowerBound();
+					lb = config.getLowerBound();
 					realVariable.setLowerBound(lb);
 				}
 				if (realVariable.isDefaultUpperBound()) {
-					ub = config.upperBound();
+					ub = config.getUpperBound();
 					realVariable.setUpperBound(ub);
 				}
 			}
diff --git a/org.emoflon.ilp/src/org/emoflon/ilp/GeneralConstraint.java b/org.emoflon.ilp/src/org/emoflon/ilp/GeneralConstraint.java
index 3a020d4..01e50d8 100644
--- a/org.emoflon.ilp/src/org/emoflon/ilp/GeneralConstraint.java
+++ b/org.emoflon.ilp/src/org/emoflon/ilp/GeneralConstraint.java
@@ -2,48 +2,51 @@
 
 import java.util.List;
 
-// Class that is currently only used for Gurobi OrConstraints
-// Could be extended for other general constraints (min, max, ...)
-public interface GeneralConstraint extends Constraint {
+/**
+ * Class that is currently only used for Gurobi OrConstraints. Could be extended
+ * for other general constraints (min, max, ...).
+ */
+public abstract class GeneralConstraint extends Constraint {
 	/**
 	 * Returns all variables that are part of the constraint.
 	 * 
 	 * @return List of variables.
 	 */
-	public List<? extends Variable<?>> getVariables();
+	public abstract List<? extends Variable<?>> getVariables();
 
 	/**
 	 * Sets the variables for this constraint.
 	 * 
 	 * @param variables List of variables.
 	 */
-	public void setVariables(List<Variable<?>> variables);
+	public abstract void setVariables(List<Variable<?>> variables);
 
 	/**
 	 * Adds one variable to the list of variables.
 	 * 
 	 * @param var New variable to be added.
 	 */
-	public void addVariable(Variable<?> var);
+	public abstract void addVariable(Variable<?> var);
 
 	/**
 	 * Returns the result variable of the constraint.
 	 * 
 	 * @return Result variable.
 	 */
-	public Variable<?> getResult();
+	public abstract Variable<?> getResult();
 
 	/**
 	 * Sets the result variable of the constraint.
 	 * 
 	 * @param res New result variable.
 	 */
-	public void setResult(Variable<?> res);
+	public abstract void setResult(Variable<?> res);
 
 	/**
 	 * Returns the type of the constraint.
 	 * 
 	 * @return Type of the constraint.
 	 */
-	public ConstraintType getType();
+	public abstract ConstraintType getType();
+
 }
diff --git a/org.emoflon.ilp/src/org/emoflon/ilp/GlpkSolver.java b/org.emoflon.ilp/src/org/emoflon/ilp/GlpkSolver.java
index 8801b35..30b311e 100644
--- a/org.emoflon.ilp/src/org/emoflon/ilp/GlpkSolver.java
+++ b/org.emoflon.ilp/src/org/emoflon/ilp/GlpkSolver.java
@@ -51,28 +51,28 @@ private void init() {
 		GLPK.glp_init_iocp(iocp);
 		// Set configuration parameters
 		// Presolve?
-		iocp.setPresolve(config.presolveEnabled() ? GLPK.GLP_ON : GLPK.GLP_OFF);
+		iocp.setPresolve(config.isPresolveEnabled() ? GLPK.GLP_ON : GLPK.GLP_OFF);
 		// Random Seed?
 		// not supported in glpk for Java
 		// --seed value is option fo glpsol
 		// Debug Output?
-		if (!config.debugOutputEnabled()) {
+		if (!config.isDebugOutputEnabled()) {
 			GLPK.glp_term_out(GLPK.GLP_OFF);
 		}
 		// Output?
-		if (config.outputEnabled()) {
-			this.outputPath = config.outputPath();
+		if (config.isOutputEnabled()) {
+			this.outputPath = config.getOutputPath();
 		}
 		// Tolerance?
-		if (config.toleranceEnabled()) {
-			iocp.setTol_int(config.tolerance());
-			iocp.setTol_obj(config.tolerance());
-			iocp.setMip_gap(config.tolerance());
+		if (config.isToleranceEnabled()) {
+			iocp.setTol_int(config.getTolerance());
+			iocp.setTol_obj(config.getTolerance());
+			iocp.setMip_gap(config.getTolerance());
 		}
 		// Timeout?
-		if (config.timeoutEnabled()) {
+		if (config.isTimeoutEnabled()) {
 			// GLPK expects milliseconds
-			iocp.setTm_lim((int) config.timeout() * 1000);
+			iocp.setTm_lim((int) config.getTimeout() * 1000);
 		}
 
 	}
@@ -80,6 +80,7 @@ private void init() {
 	@Override
 	public void buildILPProblem(Problem problem) {
 		this.problem = problem;
+		problem.validateConstraints();
 
 		// Quadratic Constraints or Functions are not supported by GLPK
 		if (problem.getConstraints().stream().anyMatch(QuadraticConstraint.class::isInstance)
@@ -139,13 +140,13 @@ private void translateVariables(Map<String, Variable<?>> vars) {
 				break;
 			case INTEGER:
 				// Check if other bounds are defined in the solver config
-				if (config.boundsEnabled()) {
+				if (config.isBoundsEnabled()) {
 					if (((IntegerVariable) var).isDefaultLowerBound()) {
-						lb = config.lowerBound();
+						lb = config.getLowerBound();
 						((IntegerVariable) var).setLowerBound((int) lb);
 					}
 					if (((IntegerVariable) var).isDefaultUpperBound()) {
-						ub = config.upperBound();
+						ub = config.getUpperBound();
 						((IntegerVariable) var).setUpperBound((int) ub);
 					}
 				}
@@ -153,13 +154,13 @@ private void translateVariables(Map<String, Variable<?>> vars) {
 				break;
 			case REAL:
 				// Check if other bounds are defined in the solver config
-				if (config.boundsEnabled()) {
+				if (config.isBoundsEnabled()) {
 					if (((RealVariable) var).isDefaultLowerBound()) {
-						lb = config.lowerBound();
+						lb = config.getLowerBound();
 						((RealVariable) var).setLowerBound(lb);
 					}
 					if (((RealVariable) var).isDefaultUpperBound()) {
-						ub = config.upperBound();
+						ub = config.getUpperBound();
 						((RealVariable) var).setUpperBound(ub);
 					}
 				}
diff --git a/org.emoflon.ilp/src/org/emoflon/ilp/GurobiSolver.java b/org.emoflon.ilp/src/org/emoflon/ilp/GurobiSolver.java
index e885562..1a91f0c 100644
--- a/org.emoflon.ilp/src/org/emoflon/ilp/GurobiSolver.java
+++ b/org.emoflon.ilp/src/org/emoflon/ilp/GurobiSolver.java
@@ -57,31 +57,31 @@ private void init() throws GRBException {
 
 		// set configuration parameters
 		// Presolve?
-		env.set(IntParam.Presolve, config.presolveEnabled() ? 1 : 0);
+		env.set(IntParam.Presolve, config.isPresolveEnabled() ? 1 : 0);
 		// Random Seed?
-		if (config.randomSeedEnabled()) {
-			env.set(IntParam.Seed, config.randomSeed());
+		if (config.isRandomSeedEnabled()) {
+			env.set(IntParam.Seed, config.getRandomSeed());
 		}
 		// Output?
-		if (!config.debugOutputEnabled()) {
+		if (!config.isDebugOutputEnabled()) {
 			env.set(IntParam.OutputFlag, 0);
 		}
 		// Tolerance?
-		if (config.toleranceEnabled()) {
-			env.set(DoubleParam.OptimalityTol, config.tolerance());
-			env.set(DoubleParam.IntFeasTol, config.tolerance());
+		if (config.isToleranceEnabled()) {
+			env.set(DoubleParam.OptimalityTol, config.getTolerance());
+			env.set(DoubleParam.IntFeasTol, config.getTolerance());
 		}
 		// Timeout?
-		if (config.timeoutEnabled()) {
-			env.set(DoubleParam.TimeLimit, config.timeout());
+		if (config.isTimeoutEnabled()) {
+			env.set(DoubleParam.TimeLimit, config.getTimeout());
 		}
 
 		// create new Gurobi Model/Problem
 		model = new GRBModel(env);
 
 		// set output path, if configured
-		if (config.outputEnabled()) {
-			this.outputPath = config.outputPath();
+		if (config.isOutputEnabled()) {
+			this.outputPath = config.getOutputPath();
 		}
 
 		grbVars.clear();
@@ -91,6 +91,7 @@ private void init() throws GRBException {
 	@Override
 	public void buildILPProblem(Problem problem) {
 		this.problem = problem;
+		problem.validateConstraints();
 
 		// Substitute Or Constraints
 		problem.substituteOr();
@@ -217,7 +218,7 @@ private void translateNormalConstraint(NormalConstraint constraint) {
 				tempLin.addTerm(term.getWeight(), grbVars.get(term.getVar1().getName()));
 			}
 			try {
-				model.addConstr(tempLin, op, rhs, constraint.toString());
+				model.addConstr(tempLin, op, rhs, constraint.getName());
 			} catch (GRBException e) {
 				throw new RuntimeException(e);
 			}
@@ -233,7 +234,7 @@ private void translateNormalConstraint(NormalConstraint constraint) {
 				}
 			}
 			try {
-				model.addQConstr(tempQuad, op, rhs, constraint.toString());
+				model.addQConstr(tempQuad, op, rhs, constraint.getName());
 			} catch (GRBException e) {
 				throw new RuntimeException(e);
 			}
@@ -280,7 +281,7 @@ private void translateGeneralConstraint(GeneralConstraint constraint) {
 					}
 				}
 				model.addGenConstrOr(model.addVar(0.0, 1.0, 0.0, GRB.BINARY, res.getName()), grbVars,
-						constraint.toString());
+						constraint.getName());
 			} catch (GRBException e) {
 				throw new RuntimeException(e);
 			}
@@ -353,13 +354,13 @@ private GRBVar translateIntegerVariable(IntegerVariable variable) {
 			int lb = variable.getLowerBound();
 			int ub = variable.getUpperBound();
 
-			if (config.boundsEnabled()) {
+			if (config.isBoundsEnabled()) {
 				if (variable.isDefaultLowerBound()) {
-					lb = config.lowerBound();
+					lb = config.getLowerBound();
 					variable.setLowerBound((int) lb);
 				}
 				if (variable.isDefaultUpperBound()) {
-					ub = config.upperBound();
+					ub = config.getUpperBound();
 					variable.setUpperBound((int) ub);
 				}
 			}
@@ -386,13 +387,13 @@ private GRBVar translateRealVariable(RealVariable variable) {
 			double lb = variable.getLowerBound();
 			double ub = variable.getUpperBound();
 
-			if (config.boundsEnabled()) {
+			if (config.isBoundsEnabled()) {
 				if (variable.isDefaultLowerBound()) {
-					lb = config.lowerBound();
+					lb = config.getLowerBound();
 					variable.setLowerBound(lb);
 				}
 				if (variable.isDefaultUpperBound()) {
-					ub = config.upperBound();
+					ub = config.getUpperBound();
 					variable.setUpperBound(ub);
 				}
 			}
diff --git a/org.emoflon.ilp/src/org/emoflon/ilp/LinearConstraint.java b/org.emoflon.ilp/src/org/emoflon/ilp/LinearConstraint.java
index 75a34e0..252a43b 100644
--- a/org.emoflon.ilp/src/org/emoflon/ilp/LinearConstraint.java
+++ b/org.emoflon.ilp/src/org/emoflon/ilp/LinearConstraint.java
@@ -11,7 +11,7 @@
  * 
  * w_1 * x_1 + w_2 * x_2 + ... (>= | > | = | != | < | <=) rhs
  */
-public class LinearConstraint implements NormalConstraint {
+public class LinearConstraint extends NormalConstraint {
 
 	private List<Term> lhsTerms = new ArrayList<Term>();
 	private Operator op;
diff --git a/org.emoflon.ilp/src/org/emoflon/ilp/NormalConstraint.java b/org.emoflon.ilp/src/org/emoflon/ilp/NormalConstraint.java
index da349bc..97b03ae 100644
--- a/org.emoflon.ilp/src/org/emoflon/ilp/NormalConstraint.java
+++ b/org.emoflon.ilp/src/org/emoflon/ilp/NormalConstraint.java
@@ -2,7 +2,7 @@
 
 import java.util.List;
 
-public interface NormalConstraint extends Constraint {
+public abstract class NormalConstraint extends Constraint {
 
 	/**
 	 * Returns a list of the terms on the left-hand side of the constraint.
@@ -10,7 +10,7 @@ public interface NormalConstraint extends Constraint {
 	 * @return Current list of terms on the left-hand side of the constraint.
 	 * @see Term
 	 */
-	public List<Term> getLhsTerms();
+	public abstract List<Term> getLhsTerms();
 
 	/**
 	 * Sets the terms of the constraint.
@@ -18,7 +18,7 @@ public interface NormalConstraint extends Constraint {
 	 * @param lhsTerms New list of terms to be set for the constraint.
 	 * @see Term
 	 */
-	public void setLhsTerms(List<Term> lhsTerms);
+	public abstract void setLhsTerms(final List<Term> lhsTerms);
 
 	/**
 	 * Adds a term to the existing terms on the left-hand side of the constraint.
@@ -26,7 +26,7 @@ public interface NormalConstraint extends Constraint {
 	 * @param term New term to be added to the constraint.
 	 * @see Term
 	 */
-	public void addTerm(Term term);
+	public abstract void addTerm(final Term term);
 
 	/**
 	 * Returns the operator of the constraint.
@@ -34,7 +34,7 @@ public interface NormalConstraint extends Constraint {
 	 * @return Current operator of the constraint.
 	 * @see Operator
 	 */
-	public Operator getOp();
+	public abstract Operator getOp();
 
 	/**
 	 * Sets the operator of the constraint.
@@ -42,21 +42,21 @@ public interface NormalConstraint extends Constraint {
 	 * @param op Operator to be set for the constraint.
 	 * @see Operator
 	 */
-	public void setOp(Operator op);
+	public abstract void setOp(final Operator op);
 
 	/**
 	 * Returns the value on the right-hand side of the constraint.
 	 * 
 	 * @return Current Value on the right-hand side.
 	 */
-	public double getRhs();
+	public abstract double getRhs();
 
 	/**
 	 * Sets the value on the right-hand side of the constraint.
 	 * 
 	 * @param rhs New value on the right-hand side.
 	 */
-	public void setRhs(double rhs);
+	public abstract void setRhs(final double rhs);
 
 	/**
 	 * Returns the type of the constraint.
@@ -64,7 +64,7 @@ public interface NormalConstraint extends Constraint {
 	 * @return Type of the constraint.
 	 * @see ConstraintType
 	 */
-	public ConstraintType getType();
+	public abstract ConstraintType getType();
 
 	/**
 	 * Converts the constraint to a list of new constraints, if needed. Only
@@ -72,6 +72,6 @@ public interface NormalConstraint extends Constraint {
 	 * 
 	 * @return List of substitution constraints or empty list.
 	 */
-	public List<Constraint> convertOperator();
+	public abstract List<Constraint> convertOperator();
 
 }
diff --git a/org.emoflon.ilp/src/org/emoflon/ilp/OrConstraint.java b/org.emoflon.ilp/src/org/emoflon/ilp/OrConstraint.java
index b734bf3..c85029a 100644
--- a/org.emoflon.ilp/src/org/emoflon/ilp/OrConstraint.java
+++ b/org.emoflon.ilp/src/org/emoflon/ilp/OrConstraint.java
@@ -11,7 +11,7 @@
  *
  * @see LinearConstraint
  */
-public class OrConstraint implements Constraint {
+public class OrConstraint extends Constraint {
 
 	private List<LinearConstraint> constraints;
 	private double epsilon = 1.0E-4;
diff --git a/org.emoflon.ilp/src/org/emoflon/ilp/OrVarsConstraint.java b/org.emoflon.ilp/src/org/emoflon/ilp/OrVarsConstraint.java
index 36dd651..338ed19 100644
--- a/org.emoflon.ilp/src/org/emoflon/ilp/OrVarsConstraint.java
+++ b/org.emoflon.ilp/src/org/emoflon/ilp/OrVarsConstraint.java
@@ -5,7 +5,7 @@
 
 // Currently only used for Gurobi OrConstraints
 // b_result = or(var1, var2, ..., var_n)
-public class OrVarsConstraint implements GeneralConstraint {
+public class OrVarsConstraint extends GeneralConstraint {
 
 	private List<BinaryVariable> variables;
 	private BinaryVariable result;
diff --git a/org.emoflon.ilp/src/org/emoflon/ilp/Problem.java b/org.emoflon.ilp/src/org/emoflon/ilp/Problem.java
index f718848..73652c3 100644
--- a/org.emoflon.ilp/src/org/emoflon/ilp/Problem.java
+++ b/org.emoflon.ilp/src/org/emoflon/ilp/Problem.java
@@ -6,6 +6,8 @@
 import java.util.Map;
 import java.util.stream.Collectors;
 
+import org.junit.AssumptionViolatedException;
+
 /**
  * This class represents the problem to be solved.
  *
@@ -14,13 +16,15 @@ public class Problem {
 
 	private Function objective;
 	private ObjectiveType type = ObjectiveType.MIN;
-	private List<NormalConstraint> constraints = new ArrayList<NormalConstraint>();
-	private List<GeneralConstraint> genConstraints = new ArrayList<GeneralConstraint>();
-	private List<SOS1Constraint> sosConstraints = new ArrayList<SOS1Constraint>();
-	private List<OrConstraint> orConstraints = new ArrayList<OrConstraint>();
+	private Map<String, NormalConstraint> constraints = new HashMap<String, NormalConstraint>();
+	private Map<String, GeneralConstraint> genConstraints = new HashMap<String, GeneralConstraint>();
+	private Map<String, SOS1Constraint> sosConstraints = new HashMap<String, SOS1Constraint>();
+	private Map<String, OrConstraint> orConstraints = new HashMap<String, OrConstraint>();
 
 	private Map<String, Variable<?>> variables = new HashMap<String, Variable<?>>();
 
+	private int constraintNameGenCounter = 0;
+
 	/**
 	 * The constructor for a problem.
 	 */
@@ -105,7 +109,7 @@ public void setOrConstraints(List<OrConstraint> constraints) {
 	 * @see QuadraticConstraint
 	 */
 	public List<NormalConstraint> getConstraints() {
-		return constraints;
+		return new ArrayList<NormalConstraint>(this.constraints.values());
 	}
 
 	/**
@@ -114,7 +118,7 @@ public List<NormalConstraint> getConstraints() {
 	 * @return List of all general constraints.
 	 */
 	public List<GeneralConstraint> getGeneralConstraints() {
-		return genConstraints;
+		return new ArrayList<GeneralConstraint>(this.genConstraints.values());
 	}
 
 	/**
@@ -124,7 +128,7 @@ public List<GeneralConstraint> getGeneralConstraints() {
 	 * @see SOS1Constraint
 	 */
 	public List<SOS1Constraint> getSOSConstraints() {
-		return sosConstraints;
+		return new ArrayList<SOS1Constraint>(this.sosConstraints.values());
 	}
 
 	/**
@@ -134,7 +138,7 @@ public List<SOS1Constraint> getSOSConstraints() {
 	 * @see OrConstraint
 	 */
 	public List<OrConstraint> getOrConstraints() {
-		return orConstraints;
+		return new ArrayList<OrConstraint>(this.orConstraints.values());
 	}
 
 	/**
@@ -196,7 +200,7 @@ public void setObjective(Function objective, ObjectiveType type) {
 	 * Sets the objective function of this problem to an empty linear function.
 	 */
 	public void setObjective() {
-		if (objective.getTerms().isEmpty()) {
+		if (objective != null && objective.getTerms().isEmpty()) {
 			System.out.println("WARNING: The objective function of this problem is empty.");
 		}
 		this.objective = new LinearFunction();
@@ -257,6 +261,19 @@ public int getVariableCount() {
 		return variables.size();
 	}
 
+	/**
+	 * If the given constraint does not have a name, yet, this method sets a generic
+	 * (unique) name.
+	 * 
+	 * @param constraint Constraint to set a generic (unique) name for.
+	 */
+	private void genConstraintNameIfAbsent(final Constraint constraint) {
+		// If constraint has no name, generate one
+		if (constraint.getName() == null || constraint.getName().isBlank()) {
+			constraint.setName("cnstr_" + constraintNameGenCounter++);
+		}
+	}
+
 	/**
 	 * Adds a normal constraint to the current constraints.
 	 * 
@@ -265,16 +282,14 @@ public int getVariableCount() {
 	 * @see QuadraticConstraint
 	 */
 	public void add(NormalConstraint constraint) {
-		if (constraint.getLhsTerms().isEmpty()) {
-			throw new IllegalArgumentException("The left-hand side of a Constraint must not be empty!");
-		}
+		genConstraintNameIfAbsent(constraint);
 		for (Term term : constraint.getLhsTerms()) {
 			variables.put(term.getVar1().getName(), term.getVar1());
 			if (term instanceof QuadraticTerm) {
 				variables.put(((QuadraticTerm) term).getVar2().getName(), ((QuadraticTerm) term).getVar2());
 			}
 		}
-		constraints.add(constraint);
+		constraints.put(constraint.getName(), constraint);
 	}
 
 	/**
@@ -283,14 +298,12 @@ public void add(NormalConstraint constraint) {
 	 * @param constraint General constraint to be added to this problem.
 	 */
 	public void add(GeneralConstraint constraint) {
-		if (constraint.getVariables().isEmpty()) {
-			throw new IllegalArgumentException("The variables of a General Constraint must not be empty!");
-		}
+		genConstraintNameIfAbsent(constraint);
 		for (Variable<?> var : constraint.getVariables()) {
 			variables.put(var.getName(), var);
 		}
 		variables.put(constraint.getResult().getName(), constraint.getResult());
-		genConstraints.add(constraint);
+		genConstraints.put(constraint.getName(), constraint);
 	}
 
 	/**
@@ -300,15 +313,11 @@ public void add(GeneralConstraint constraint) {
 	 * @see SOS1Constraint
 	 */
 	public void add(SOS1Constraint constraint) {
-		if (constraint.getVariables().isEmpty()) {
-			throw new IllegalArgumentException("The variables of a SOS Constraint must not be empty!");
-		} else if (constraint.getVariables().size() != constraint.getWeights().length) {
-			throw new IllegalArgumentException("Every variable in a SOS Constraint should be assigned with a weight!");
-		}
+		genConstraintNameIfAbsent(constraint);
 		for (Variable<?> var : constraint.getVariables()) {
 			variables.put(var.getName(), var);
 		}
-		sosConstraints.add(constraint);
+		sosConstraints.put(constraint.getName(), constraint);
 	}
 
 	/**
@@ -318,15 +327,13 @@ public void add(SOS1Constraint constraint) {
 	 * @see OrConstraint
 	 */
 	public void add(OrConstraint constraint) {
-		if (constraint.getConstraints().isEmpty()) {
-			throw new IllegalArgumentException("The constraints of a Or Constraint must not be empty!");
-		}
+		genConstraintNameIfAbsent(constraint);
 		for (LinearConstraint lin : constraint.getConstraints()) {
 			for (Term term : lin.getLhsTerms()) {
 				variables.put(term.getVar1().getName(), term.getVar1());
 			}
 		}
-		orConstraints.add(constraint);
+		orConstraints.put(constraint.getName(), constraint);
 	}
 
 	/**
@@ -338,7 +345,7 @@ public void add(OrConstraint constraint) {
 	 *         problem formulation.
 	 */
 	public boolean remove(NormalConstraint constraint) {
-		return constraints.remove(constraint);
+		return constraints.remove(constraint.getName()) != null;
 	}
 
 	/**
@@ -350,7 +357,7 @@ public boolean remove(NormalConstraint constraint) {
 	 *         problem formulation.
 	 */
 	public boolean remove(GeneralConstraint constraint) {
-		return genConstraints.remove(constraint);
+		return genConstraints.remove(constraint.getName()) != null;
 	}
 
 	/**
@@ -362,7 +369,7 @@ public boolean remove(GeneralConstraint constraint) {
 	 *         problem formulation.
 	 */
 	public boolean remove(SOS1Constraint constraint) {
-		return sosConstraints.remove(constraint);
+		return sosConstraints.remove(constraint.getName()) != null;
 	}
 
 	/**
@@ -374,7 +381,7 @@ public boolean remove(SOS1Constraint constraint) {
 	 *         problem formulation.
 	 */
 	public boolean remove(OrConstraint constraint) {
-		return orConstraints.remove(constraint);
+		return orConstraints.remove(constraint.getName()) != null;
 	}
 
 	/**
@@ -437,7 +444,9 @@ public void substituteOperators() {
 					.map(SOS1Constraint.class::cast).collect(Collectors.toList()));
 		}
 		// delete converted constraints
-		this.constraints.removeAll(delete);
+		for (final NormalConstraint toDelete : delete) {
+			this.constraints.remove(toDelete.getName());
+		}
 		delete.forEach(it -> this.remove(it));
 
 		// add substitutions
@@ -467,4 +476,69 @@ public void substituteSOS1() {
 		sosConstraints.clear();
 	}
 
-}
\ No newline at end of file
+	/**
+	 * Returns the constraint for the given name or throws an error if there is no
+	 * constraint with a matching name.
+	 * 
+	 * @param name Constraint name to search for.
+	 * @return Constraint for the given name.
+	 */
+	public Constraint getConstraintByName(final String name) {
+		if (this.constraints.containsKey(name)) {
+			return this.constraints.get(name);
+		} else if (this.genConstraints.containsKey(name)) {
+			return this.genConstraints.get(name);
+		} else if (this.sosConstraints.containsKey(name)) {
+			return this.sosConstraints.get(name);
+		} else if (this.orConstraints.containsKey(name)) {
+			return this.orConstraints.get(name);
+		} else {
+			throw new Error("Constraint with name " + name + " not found.");
+		}
+	}
+
+	/**
+	 * Returns true if the problem contains a constraint with the given name.
+	 * 
+	 * @param name Name to check the constraint existence for.
+	 * @return True if the problem contains a constraint with the given name.
+	 */
+	public boolean hasConstraintWithName(final String name) {
+		return this.constraints.containsKey(name) || this.genConstraints.containsKey(name)
+				|| this.sosConstraints.containsKey(name) || this.orConstraints.containsKey(name);
+	}
+
+	/**
+	 * Validates all constraints that are part of this problem instance.
+	 */
+	public void validateConstraints() {
+		this.constraints.values().forEach(v -> {
+			if (v.getLhsTerms().isEmpty()) {
+				throw new AssumptionViolatedException("The constraint " + v.getName() + " has no LHS terms.");
+			}
+		});
+
+		this.genConstraints.values().forEach(v -> {
+			if (v.getVariables().isEmpty()) {
+				throw new AssumptionViolatedException("The generic constraint " + v.getName() + " has no variables.");
+			}
+		});
+
+		this.sosConstraints.values().forEach(v -> {
+			if (v.getVariables().isEmpty()) {
+				throw new AssumptionViolatedException("The SOS1 constraint " + v.getName() + " has no variables.");
+			}
+			if (v.getVariables().size() != v.getWeights().length) {
+				throw new AssumptionViolatedException("The SOS1 constraint " + v.getName()
+						+ " does not contain the correct amount of weights for the number of variables.");
+			}
+		});
+
+		this.orConstraints.values().forEach(v -> {
+			if (v.getConstraints().isEmpty()) {
+				throw new AssumptionViolatedException("The Or constraint " + v.getName() + " has no sub constraints.");
+			}
+		});
+	}
+
+}
diff --git a/org.emoflon.ilp/src/org/emoflon/ilp/QuadraticConstraint.java b/org.emoflon.ilp/src/org/emoflon/ilp/QuadraticConstraint.java
index 7a36206..383e8a4 100644
--- a/org.emoflon.ilp/src/org/emoflon/ilp/QuadraticConstraint.java
+++ b/org.emoflon.ilp/src/org/emoflon/ilp/QuadraticConstraint.java
@@ -13,7 +13,7 @@
  * 
  * w_1 * x_1 + w_2 * x_2 + ... (>= | > | = | != | < | <=) rhs
  */
-public class QuadraticConstraint implements NormalConstraint {
+public class QuadraticConstraint extends NormalConstraint {
 
 	private List<Term> lhsTerms;
 	private Operator op;
diff --git a/org.emoflon.ilp/src/org/emoflon/ilp/SOS1Constraint.java b/org.emoflon.ilp/src/org/emoflon/ilp/SOS1Constraint.java
index 13aea63..7e02f3e 100644
--- a/org.emoflon.ilp/src/org/emoflon/ilp/SOS1Constraint.java
+++ b/org.emoflon.ilp/src/org/emoflon/ilp/SOS1Constraint.java
@@ -12,7 +12,7 @@
  * SOS1(var_1, var_2, ..., var_n) with weights w = [w_1, w_2, ..., w_n]
  *
  */
-public class SOS1Constraint implements Constraint {
+public class SOS1Constraint extends Constraint {
 
 	private List<Variable<?>> variables = new ArrayList<Variable<?>>();
 	private List<Double> weights = new ArrayList<Double>();
diff --git a/org.emoflon.ilp/src/org/emoflon/ilp/SolverConfig.java b/org.emoflon.ilp/src/org/emoflon/ilp/SolverConfig.java
index a91f2f7..9dc3e44 100644
--- a/org.emoflon.ilp/src/org/emoflon/ilp/SolverConfig.java
+++ b/org.emoflon.ilp/src/org/emoflon/ilp/SolverConfig.java
@@ -1,46 +1,208 @@
 package org.emoflon.ilp;
 
-import org.emoflon.ilp.SolverConfig.SolverType;
-
 /**
- * This record class represents the configuration parameters used to configure
- * the solver.
- * 
- * @param type               Solver Type (GUROBI, GLPK, CPLEX)
- * @param timeoutEnabled     Set to true, if timeout should be set.
- * @param timeout            time until timeout
- * @param randomSeedEnabled  Set to true, if a seed should be set (if possible).
- * @param randomSeed         Value for the random seed.
- * @param toleranceEnabled   Set to true, if a value for the tolerance should be
- *                           set.
- * @param tolerance          Value for the tolerance.
- * @param boundsEnabled      Set to true, if custom default bounds for integer
- *                           and real variables should be set.
- * @param lowerBound         Value for the custom upper bound for integer and
- *                           real variables.
- * @param upperBound         Value for the custom upper bound for integer and
- *                           real variables.
- * @param presolveEnabled    Set to true, if the solver should carry out a
- *                           presolve phase (for GPLK you might need to set this
- *                           to true!).
- * @param debugOutputEnabled Set to true, if debug output should be written into
- *                           a file.
- * @param outputEnabled      Set to true, if the problem should be written into
- *                           a file (e.g. with the file ending ".lp")
- * @param outputPath         Path to the output file.
- *
+ * This class represents the configuration parameters used to configure the
+ * solver.
  */
-public record SolverConfig(SolverType solver, boolean timeoutEnabled, double timeout, boolean randomSeedEnabled,
-		int randomSeed, boolean toleranceEnabled, double tolerance, boolean boundsEnabled, int lowerBound,
-		int upperBound, boolean presolveEnabled, boolean debugOutputEnabled, boolean outputEnabled, String outputPath) {
+public class SolverConfig {
+	private SolverType solver;
+	private boolean timeoutEnabled;
+	private double timeout;
+	private boolean randomSeedEnabled;
+	private int randomSeed;
+	private boolean toleranceEnabled;
+	private double tolerance;
+	private boolean boundsEnabled;
+	private int lowerBound;
+	private int upperBound;
+	private boolean presolveEnabled;
+	private boolean debugOutputEnabled;
+	private boolean outputEnabled;
+	private String outputPath;
+
+	/**
+	 * Creates a new instance of the solver configuration.
+	 * 
+	 * @param type               Solver Type (GUROBI, GLPK, CPLEX)
+	 * @param timeoutEnabled     Set to true, if timeout should be set.
+	 * @param timeout            time until timeout
+	 * @param randomSeedEnabled  Set to true, if a seed should be set (if possible).
+	 * @param randomSeed         Value for the random seed.
+	 * @param toleranceEnabled   Set to true, if a value for the tolerance should be
+	 *                           set.
+	 * @param tolerance          Value for the tolerance.
+	 * @param boundsEnabled      Set to true, if custom default bounds for integer
+	 *                           and real variables should be set.
+	 * @param lowerBound         Value for the custom upper bound for integer and
+	 *                           real variables.
+	 * @param upperBound         Value for the custom upper bound for integer and
+	 *                           real variables.
+	 * @param presolveEnabled    Set to true, if the solver should carry out a
+	 *                           presolve phase (for GPLK you might need to set this
+	 *                           to true!).
+	 * @param debugOutputEnabled Set to true, if debug output should be written into
+	 *                           a file.
+	 * @param outputEnabled      Set to true, if the problem should be written into
+	 *                           a file (e.g. with the file ending ".lp")
+	 * @param outputPath         Path to the output file.
+	 */
+	public SolverConfig(SolverType solver, boolean timeoutEnabled, double timeout, boolean randomSeedEnabled,
+			int randomSeed, boolean toleranceEnabled, double tolerance, boolean boundsEnabled, int lowerBound,
+			int upperBound, boolean presolveEnabled, boolean debugOutputEnabled, boolean outputEnabled,
+			String outputPath) {
+		this.solver = solver;
+
+		this.timeoutEnabled = timeoutEnabled;
+		this.timeout = timeout;
+		this.randomSeedEnabled = randomSeedEnabled;
+		this.randomSeed = randomSeed;
+		this.toleranceEnabled = toleranceEnabled;
+		this.tolerance = tolerance;
+		this.boundsEnabled = boundsEnabled;
+		this.lowerBound = lowerBound;
+		this.upperBound = upperBound;
+		this.presolveEnabled = presolveEnabled;
+		this.debugOutputEnabled = debugOutputEnabled;
+		this.outputEnabled = outputEnabled;
+		this.outputPath = outputPath;
+	}
+
+	public SolverConfig() {
+		this.solver = SolverType.GLPK;
+		this.timeoutEnabled = false;
+		this.timeout = -1;
+		this.randomSeedEnabled = false;
+		this.randomSeed = -1;
+		this.toleranceEnabled = false;
+		this.tolerance = -1;
+		this.boundsEnabled = false;
+		this.lowerBound = -1;
+		this.upperBound = -1;
+		this.presolveEnabled = true;
+		this.debugOutputEnabled = true;
+		this.outputEnabled = false;
+		this.outputPath = "/dev/null";
+	}
 
 	/**
 	 * Type of the Solver <br>
-	 * <br>
 	 * 
-	 * GUROBI, GLPK or CPLEX
+	 * GUROBI, GLPK, or CPLEX
 	 */
 	public enum SolverType {
 		GUROBI, CPLEX, GLPK
 	}
+
+	public SolverType getSolver() {
+		return solver;
+	}
+
+	public void setSolver(final SolverType solver) {
+		this.solver = solver;
+	}
+
+	public boolean isTimeoutEnabled() {
+		return timeoutEnabled;
+	}
+
+	public void setTimeoutEnabled(final boolean timeoutEnabled) {
+		this.timeoutEnabled = timeoutEnabled;
+	}
+
+	public double getTimeout() {
+		return timeout;
+	}
+
+	public void setTimeout(final double timeout) {
+		this.timeout = timeout;
+	}
+
+	public boolean isRandomSeedEnabled() {
+		return randomSeedEnabled;
+	}
+
+	public void setRandomSeedEnabled(final boolean randomSeedEnabled) {
+		this.randomSeedEnabled = randomSeedEnabled;
+	}
+
+	public int getRandomSeed() {
+		return randomSeed;
+	}
+
+	public void setRandomSeed(final int randomSeed) {
+		this.randomSeed = randomSeed;
+	}
+
+	public boolean isToleranceEnabled() {
+		return toleranceEnabled;
+	}
+
+	public void setToleranceEnabled(final boolean toleranceEnabled) {
+		this.toleranceEnabled = toleranceEnabled;
+	}
+
+	public double getTolerance() {
+		return tolerance;
+	}
+
+	public void setTolerance(final double tolerance) {
+		this.tolerance = tolerance;
+	}
+
+	public boolean isBoundsEnabled() {
+		return boundsEnabled;
+	}
+
+	public void setBoundsEnabled(final boolean boundsEnabled) {
+		this.boundsEnabled = boundsEnabled;
+	}
+
+	public int getLowerBound() {
+		return lowerBound;
+	}
+
+	public void setLowerBound(final int lowerBound) {
+		this.lowerBound = lowerBound;
+	}
+
+	public int getUpperBound() {
+		return upperBound;
+	}
+
+	public void setUpperBound(final int upperBound) {
+		this.upperBound = upperBound;
+	}
+
+	public boolean isPresolveEnabled() {
+		return presolveEnabled;
+	}
+
+	public void setPresolveEnabled(final boolean presolveEnabled) {
+		this.presolveEnabled = presolveEnabled;
+	}
+
+	public boolean isDebugOutputEnabled() {
+		return debugOutputEnabled;
+	}
+
+	public void setDebugOutputEnabled(final boolean debugOutputEnabled) {
+		this.debugOutputEnabled = debugOutputEnabled;
+	}
+
+	public boolean isOutputEnabled() {
+		return outputEnabled;
+	}
+
+	public void setOutputEnabled(final boolean outputEnabled) {
+		this.outputEnabled = outputEnabled;
+	}
+
+	public String getOutputPath() {
+		return outputPath;
+	}
+
+	public void setOutputPath(final String outputPath) {
+		this.outputPath = outputPath;
+	}
+
 }
diff --git a/org.emoflon.ilp/src/org/emoflon/ilp/SolverHelper.java b/org.emoflon.ilp/src/org/emoflon/ilp/SolverHelper.java
index 3230345..b4f9c3c 100644
--- a/org.emoflon.ilp/src/org/emoflon/ilp/SolverHelper.java
+++ b/org.emoflon.ilp/src/org/emoflon/ilp/SolverHelper.java
@@ -18,7 +18,7 @@ public class SolverHelper {
 	 * @see SolverConfig
 	 */
 	public SolverHelper(SolverConfig config) {
-		switch (config.solver()) {
+		switch (config.getSolver()) {
 		case GUROBI:
 			this.solver = new GurobiSolver(config);
 			break;