diff --git a/src/main/java/neqsim/thermo/system/SystemInterface.java b/src/main/java/neqsim/thermo/system/SystemInterface.java
index ff9fa3b18..c8abf0c46 100644
--- a/src/main/java/neqsim/thermo/system/SystemInterface.java
+++ b/src/main/java/neqsim/thermo/system/SystemInterface.java
@@ -1813,10 +1813,8 @@ public double calcBeta()
    * <p>
    * initBeta.
    * </p>
-   *
-   * @return a double
    */
-  public double initBeta();
+  public void initBeta();
 
   /**
    * <p>
diff --git a/src/main/java/neqsim/thermo/system/SystemThermo.java b/src/main/java/neqsim/thermo/system/SystemThermo.java
index 30cb69a55..62b5ef78b 100644
--- a/src/main/java/neqsim/thermo/system/SystemThermo.java
+++ b/src/main/java/neqsim/thermo/system/SystemThermo.java
@@ -39,36 +39,43 @@
 /*
  * This is the base class of the System classes.
  */
-
 abstract class SystemThermo implements SystemInterface {
   private static final long serialVersionUID = 1000;
+  static Logger logger = LogManager.getLogger(SystemThermo.class);
+
   // Class variables
+  private static final int MAX_PHASES = 6;
 
-  private boolean implementedTemperatureDeriativesofFugacity = true;
-  private boolean implementedPressureDeriativesofFugacity = true;
-  private boolean implementedCompositionDeriativesofFugacity = true;
-  protected double criticalTemperature = 0;
-  protected String[][] resultTable = null;
-  boolean isInitialized = false;
+  // Object metadata
   protected String fluidInfo = "No Information Available";
   protected String fluidName = "DefaultName";
-
   protected String modelName = "Default";
 
+  // Initialization
+  boolean isInitialized = false;
   protected boolean numericDerivatives = false;
+  protected int initType = 3;
+
+  private boolean implementedTemperatureDeriativesofFugacity = true;
+  private boolean implementedPressureDeriativesofFugacity = true;
+  private boolean implementedCompositionDeriativesofFugacity = true;
+  protected double criticalTemperature = 0;
+  protected String[][] resultTable = null;
 
   protected boolean allowPhaseShift = true;
 
   private boolean useTVasIndependentVariables = false;
   protected double criticalPressure = 0;
   private double totalNumberOfMoles = 0;
+
+  // todo: componentNameTag is not working yet, a kind of alias-postfix for Components from this
+  // system that will be passed on to other systems. used to find originator of specific components
+  // or
   public String componentNameTag = "";
   protected neqsim.thermo.characterization.WaxCharacterise waxCharacterisation = null;
-  protected double[] beta = new double[6];
+  protected double[] beta = new double[MAX_PHASES];
   protected int a;
 
-  protected int initType = 3;
-
   private ArrayList<String> componentNames = new ArrayList<String>();
   // protected ArrayList<String> resultArray1 = new ArrayList<String>();
   protected String[] CapeOpenProperties11 = {"molecularWeight", "speedOfSound",
@@ -95,28 +102,31 @@ abstract class SystemThermo implements SystemInterface {
   protected int numberOfPhases = 2;
   public int maxNumberOfPhases = 2;
   protected int attractiveTermNumber = 0;
-  protected int phase = 2;
-  protected int onePhaseType = 1; // 0 - liquid 1 - gas
+
+  // phasetype to be enum
   protected int[] phaseType = {1, 0, 0, 0, 0, 0};
+
+  // Index refers to position in phaseArray. First value of phaseIndex is the phase which is created
+  // first and the last is the phase created last.
   protected int[] phaseIndex = {0, 1, 2, 3, 4, 5};
+
+  // All phases of System. Flashes reorders phaseArray by density.
+  protected PhaseInterface[] phaseArray;
+
   protected ChemicalReactionOperations chemicalReactionOperations = null;
   private int mixingRule = 1;
   protected boolean chemicalSystem = false;
 
   protected boolean solidPhaseCheck = false;
-
   protected boolean multiPhaseCheck = false;
-
   protected boolean hydrateCheck = false;
 
   protected boolean checkStability = true;
-  protected PhaseInterface[] phaseArray;
   public neqsim.thermo.characterization.Characterise characterization = null;
   protected neqsim.standards.StandardInterface standard = null;
   protected InterphasePropertiesInterface interfaceProp = null;
   private boolean multiphaseWaxCheck = false;
   private boolean forcePhaseTypes = false;
-  static Logger logger = LogManager.getLogger(SystemThermo.class);
 
   /**
    * <p>
@@ -124,7 +134,7 @@ abstract class SystemThermo implements SystemInterface {
    * </p>
    */
   public SystemThermo() {
-    phaseArray = new PhaseInterface[6];
+    phaseArray = new PhaseInterface[MAX_PHASES];
     characterization = new Characterise(this);
     interfaceProp = new InterfaceProperties(this);
   }
@@ -178,8 +188,6 @@ public void clearAll() {
     phaseType[1] = 0;
     numberOfComponents = 0;
     setNumberOfPhases(2);
-    phase = 2;
-    onePhaseType = 1;
     beta[0] = 1.0;
     beta[1] = 1.0;
     beta[2] = 1.0;
@@ -849,7 +857,7 @@ public void addTBPfraction(String componentName, double numberOfMoles, double mo
       // // refSystem.setPressure(1.01325);
       // // refSystem.init(1);
       // //refSystem.initPhysicalProperties();
-      // // APIdens - refSystem.getPhase(1).getPhysicalProperties().getDensity();;
+      // // APIdens - refSystem.getPhase(1).getPhysicalProperties().getDensity();
       // sammenligne med API-standard for tetthet - og sette Penloux dt
     } catch (Exception ex) {
       logger.error("error", ex);
@@ -993,7 +1001,7 @@ public void addTBPfraction(String componentName, double numberOfMoles, double mo
       // // refSystem.setPressure(1.01325);
       // // refSystem.init(1);
       // // refSystem.initPhysicalProperties();
-      // // APIdens - refSystem.getPhase(1).getPhysicalProperties().getDensity();;
+      // // APIdens - refSystem.getPhase(1).getPhysicalProperties().getDensity();
       // // sammenligne med API-standard for tetthet - og sette Penloux dt
     } catch (Exception ex) {
       logger.error("error", ex);
@@ -1394,7 +1402,7 @@ public final double calcBeta() throws neqsim.util.exception.IsNaNException,
     double maxBeta = 1.0 - tolerance;
     double g0 = -1.0;
     double g1 = 1.0;
-    nybeta = beta[0];
+    nybeta = this.beta[0];
     betal = 1.0 - nybeta;
 
     for (i = 0; i < numberOfComponents; i++) {
@@ -1411,14 +1419,14 @@ public final double calcBeta() throws neqsim.util.exception.IsNaNException,
     }
 
     if (g0 < 0) {
-      beta[1] = 1.0 - tolerance;
-      beta[0] = tolerance;
-      return beta[0];
+      this.beta[1] = 1.0 - tolerance;
+      this.beta[0] = tolerance;
+      return this.beta[0];
     }
     if (g1 > 0) {
-      beta[1] = tolerance;
-      beta[0] = 1.0 - tolerance;
-      return beta[0];
+      this.beta[1] = tolerance;
+      this.beta[0] = 1.0 - tolerance;
+      return this.beta[0];
     }
 
     nybeta = (minBeta + maxBeta) / 2.0;
@@ -1525,18 +1533,18 @@ public final double calcBeta() throws neqsim.util.exception.IsNaNException,
 
     // System.out.println("beta: " + nybeta + " iterations: " + iterations);
     if (nybeta <= tolerance) {
-      phase = 1;
+      // this.phase = 1;
       nybeta = tolerance;
     } else if (nybeta >= 1.0 - tolerance) {
-      phase = 0;
+      // this.phase = 0;
       nybeta = 1.0 - tolerance;
       // superheated vapour
     } else {
-      phase = 2;
+      // this.phase = 2;
     } // two-phase liquid-gas
 
-    beta[0] = nybeta;
-    beta[1] = 1.0 - nybeta;
+    this.beta[0] = nybeta;
+    this.beta[1] = 1.0 - nybeta;
 
     if (iterations >= maxIterations) {
       throw new neqsim.util.exception.TooManyIterationsException(this, "calcBeta", maxIterations);
@@ -1548,17 +1556,16 @@ public final double calcBeta() throws neqsim.util.exception.IsNaNException,
        */
       throw new neqsim.util.exception.IsNaNException(this, "calcBeta", "beta");
     }
-    return beta[0];
+    return this.beta[0];
   }
 
   /** {@inheritDoc} */
   @Override
-  public final double initBeta() {
+  public final void initBeta() {
     for (int i = 0; i < numberOfPhases; i++) {
-      beta[phaseIndex[i]] = getPhase(i).getNumberOfMolesInPhase() / getTotalNumberOfMoles();
+      this.beta[phaseIndex[i]] = getPhase(i).getNumberOfMolesInPhase() / getTotalNumberOfMoles();
       // System.out.println("beta " + beta[i]);
     }
-    return beta[phaseIndex[0]];
   }
 
   /** {@inheritDoc} */
@@ -1726,8 +1733,7 @@ public boolean hasSolidPhase() {
   /** {@inheritDoc} */
   @Override
   public void init(int type) {
-    isInitialized = true;
-    if (numericDerivatives) {
+    if (this.numericDerivatives) {
       initNumeric(type);
     } else {
       initAnalytic(type);
@@ -1737,8 +1743,7 @@ public void init(int type) {
   /** {@inheritDoc} */
   @Override
   public void init(int type, int phase) {
-    isInitialized = true;
-    if (numericDerivatives) {
+    if (this.numericDerivatives) {
       initNumeric(type, phase);
     } else {
       initAnalytic(type, phase);
@@ -1846,6 +1851,7 @@ public void initAnalytic(int type) {
         }
       }
     }
+    this.isInitialized = true;
   }
 
   /**
@@ -1900,6 +1906,7 @@ public void initAnalytic(int type, int phase) {
         tmpPhase.setPhaseTypeName("oil");
       }
     }
+    this.isInitialized = true;
   }
 
   /**
@@ -2018,6 +2025,7 @@ public void initNumeric(int type, int phasen) {
         }
       }
     }
+    this.isInitialized = true;
   }
 
   /** {@inheritDoc} */
@@ -4770,10 +4778,11 @@ public double[] getMolarRate() {
   /** {@inheritDoc} */
   @Override
   public double[] getMolarComposition() {
-    double[] comp = new double[getPhase(0).getNumberOfComponents()];
+    PhaseInterface phase = this.getPhase(0);
+    double[] comp = new double[phase.getNumberOfComponents()];
 
     for (int compNumb = 0; compNumb < numberOfComponents; compNumb++) {
-      comp[compNumb] = getPhase(0).getComponent(compNumb).getz();
+      comp[compNumb] = phase.getComponent(compNumb).getz();
     }
     return comp;
   }