diff --git a/InnerDetector/InDetRecTools/InDetZVTOPVxFinder/InDetZVTOPVxFinder/IZVTOP_AmbiguitySolver.h b/InnerDetector/InDetRecTools/InDetZVTOPVxFinder/InDetZVTOPVxFinder/IZVTOP_AmbiguitySolver.h
index be0a7690144f98a92cbafb874e0a33c62dbe7706..0741b97fbcacbab5a0bc4c63d07f0cdfe1afd019 100755
--- a/InnerDetector/InDetRecTools/InDetZVTOPVxFinder/InDetZVTOPVxFinder/IZVTOP_AmbiguitySolver.h
+++ b/InnerDetector/InDetRecTools/InDetZVTOPVxFinder/InDetZVTOPVxFinder/IZVTOP_AmbiguitySolver.h
@@ -1,5 +1,5 @@
 /*
-  Copyright (C) 2002-2017 CERN for the benefit of the ATLAS collaboration
+  Copyright (C) 2002-2019 CERN for the benefit of the ATLAS collaboration
 */
 
 ///////////////////////////////////////////////////////////////////
@@ -17,22 +17,14 @@
 namespace InDet 
 {
 
-
-  static const InterfaceID IID_IZVTOP_AmbiguitySolver("InDet::IZVTOP_AmbiguitySolver", 1, 0);
-
   class IZVTOP_AmbiguitySolver : virtual public IAlgTool {
   public:
-    static const InterfaceID& interfaceID( ) ;
+    DeclareInterfaceID (IZVTOP_AmbiguitySolver, 1, 0);
 
     // enter declaration of your interface-defining member functions here
-    virtual std::vector< xAOD::Vertex* > solveAmbiguities(std::vector< xAOD::Vertex* > VertexContainer) = 0;
+    virtual std::vector< xAOD::Vertex* > solveAmbiguities(std::vector< xAOD::Vertex* > VertexContainer) const = 0;
   };
 
-  inline const InterfaceID& InDet::IZVTOP_AmbiguitySolver::interfaceID()
-    { 
-      return IID_IZVTOP_AmbiguitySolver; 
-    }
-
 } // end of namespace
 
 #endif 
diff --git a/InnerDetector/InDetRecTools/InDetZVTOPVxFinder/InDetZVTOPVxFinder/IZVTOP_SimpleVtxProbCalc.h b/InnerDetector/InDetRecTools/InDetZVTOPVxFinder/InDetZVTOPVxFinder/IZVTOP_SimpleVtxProbCalc.h
index 015ce332649afa9b58b508a169039eda4534423a..7e6a281a4754a2677ac1018546f71392cd96e4b5 100755
--- a/InnerDetector/InDetRecTools/InDetZVTOPVxFinder/InDetZVTOPVxFinder/IZVTOP_SimpleVtxProbCalc.h
+++ b/InnerDetector/InDetRecTools/InDetZVTOPVxFinder/InDetZVTOPVxFinder/IZVTOP_SimpleVtxProbCalc.h
@@ -1,5 +1,5 @@
 /*
-  Copyright (C) 2002-2017 CERN for the benefit of the ATLAS collaboration
+  Copyright (C) 2002-2019 CERN for the benefit of the ATLAS collaboration
 */
 
 ///////////////////////////////////////////////////////////////////
@@ -15,21 +15,14 @@ namespace InDet
 {
 
 
-  static const InterfaceID IID_IZVTOP_SimpleVtxProbCalc("InDet::IZVTOP_SimpleVtxProbCalc", 1, 0);
-
   class IZVTOP_SimpleVtxProbCalc : virtual public IAlgTool {
   public:
-    static const InterfaceID& interfaceID( ) ;
+    DeclareInterfaceID (IZVTOP_SimpleVtxProbCalc, 1, 0);
 
     // enter declaration of your interface-defining member functions here
-    virtual double calcVtxProb(double & trk_func_sum, double & trk_func_sum2) = 0;
+    virtual double calcVtxProb(double & trk_func_sum, double & trk_func_sum2) const = 0;
   };
 
-  inline const InterfaceID& InDet::IZVTOP_SimpleVtxProbCalc::interfaceID()
-    { 
-      return IID_IZVTOP_SimpleVtxProbCalc; 
-    }
-
 } // end of namespace
 
 #endif 
diff --git a/InnerDetector/InDetRecTools/InDetZVTOPVxFinder/InDetZVTOPVxFinder/IZVTOP_SpatialPointFinder.h b/InnerDetector/InDetRecTools/InDetZVTOPVxFinder/InDetZVTOPVxFinder/IZVTOP_SpatialPointFinder.h
index 86fab39fa4e89ce03656c0198a6fd5b7f082d649..42a35988ea25ebc531491759126a96cdecdc84c6 100755
--- a/InnerDetector/InDetRecTools/InDetZVTOPVxFinder/InDetZVTOPVxFinder/IZVTOP_SpatialPointFinder.h
+++ b/InnerDetector/InDetRecTools/InDetZVTOPVxFinder/InDetZVTOPVxFinder/IZVTOP_SpatialPointFinder.h
@@ -1,5 +1,5 @@
 /*
-  Copyright (C) 2002-2017 CERN for the benefit of the ATLAS collaboration
+  Copyright (C) 2002-2019 CERN for the benefit of the ATLAS collaboration
 */
 
 ///////////////////////////////////////////////////////////////////
@@ -25,28 +25,21 @@ namespace InDet
 {
 
 
-  static const InterfaceID IID_IZVTOP_SpatialPointFinder("InDet::IZVTOP_SpatialPointFinder", 1, 0);
-
   class IZVTOP_SpatialPointFinder : virtual public IAlgTool {
   public:
-    static const InterfaceID& interfaceID( ) ;
+    DeclareInterfaceID(IZVTOP_SpatialPointFinder, 1, 0);
 
     // declaration of interface-defining member functions
-    virtual Trk::Vertex* findSpatialPoint(const Trk::Track* trk_1, const Trk::Track* trk_2) = 0;
-    virtual Trk::Vertex* findSpatialPoint(const Rec::TrackParticle* trk_1, const Rec::TrackParticle* trk_2) = 0;
-    virtual Trk::Vertex* findSpatialPoint(const Trk::TrackParticleBase* trk_1, const Trk::TrackParticleBase* trk_2) = 0;
-    virtual Trk::Vertex* findSpatialPoint(const Trk::RecVertex vtx, const Trk::Track* trk_1) = 0;
-    virtual Trk::Vertex* findSpatialPoint(const Trk::RecVertex vtx, const Rec::TrackParticle* trk_1) = 0;
-    virtual Trk::Vertex* findSpatialPoint(const Trk::RecVertex vtx, const Trk::TrackParticleBase* trk_1) = 0;
-    virtual Trk::Vertex* findSpatialPoint(const Trk::TrackParameters* perigee_1, const Trk::TrackParameters* perigee_2) = 0;
-    virtual Trk::Vertex* findSpatialPoint(const Trk::RecVertex vtx, const Trk::TrackParameters* perigee_1) = 0;
+    virtual Trk::Vertex* findSpatialPoint(const Trk::Track* trk_1, const Trk::Track* trk_2) const = 0;
+    virtual Trk::Vertex* findSpatialPoint(const Rec::TrackParticle* trk_1, const Rec::TrackParticle* trk_2) const = 0;
+    virtual Trk::Vertex* findSpatialPoint(const Trk::TrackParticleBase* trk_1, const Trk::TrackParticleBase* trk_2) const = 0;
+    virtual Trk::Vertex* findSpatialPoint(const Trk::RecVertex vtx, const Trk::Track* trk_1) const = 0;
+    virtual Trk::Vertex* findSpatialPoint(const Trk::RecVertex vtx, const Rec::TrackParticle* trk_1) const = 0;
+    virtual Trk::Vertex* findSpatialPoint(const Trk::RecVertex vtx, const Trk::TrackParticleBase* trk_1) const = 0;
+    virtual Trk::Vertex* findSpatialPoint(const Trk::TrackParameters* perigee_1, const Trk::TrackParameters* perigee_2) const = 0;
+    virtual Trk::Vertex* findSpatialPoint(const Trk::RecVertex vtx, const Trk::TrackParameters* perigee_1) const = 0;
   };
 
-  inline const InterfaceID& InDet::IZVTOP_SpatialPointFinder::interfaceID()
-    { 
-      return IID_IZVTOP_SpatialPointFinder; 
-    }
-
 } // end of namespace
 
 #endif 
diff --git a/InnerDetector/InDetRecTools/InDetZVTOPVxFinder/InDetZVTOPVxFinder/IZVTOP_TrkProbTubeCalc.h b/InnerDetector/InDetRecTools/InDetZVTOPVxFinder/InDetZVTOPVxFinder/IZVTOP_TrkProbTubeCalc.h
index e28bd3f4b01d5e55f114af93b7ff91b4f84e17a2..826fcec22c477f485e5423ac19f8e68b1fbb82cd 100755
--- a/InnerDetector/InDetRecTools/InDetZVTOPVxFinder/InDetZVTOPVxFinder/IZVTOP_TrkProbTubeCalc.h
+++ b/InnerDetector/InDetRecTools/InDetZVTOPVxFinder/InDetZVTOPVxFinder/IZVTOP_TrkProbTubeCalc.h
@@ -1,5 +1,5 @@
 /*
-  Copyright (C) 2002-2017 CERN for the benefit of the ATLAS collaboration
+  Copyright (C) 2002-2019 CERN for the benefit of the ATLAS collaboration
 */
 
 ///////////////////////////////////////////////////////////////////
@@ -26,28 +26,21 @@ namespace InDet
 {
 
 
-  static const InterfaceID IID_IZVTOP_TrkProbTubeCalc("InDet::IZVTOP_TrkProbTubeCalc", 1, 0);
-
   class IZVTOP_TrkProbTubeCalc : virtual public IAlgTool {
   public:
-    static const InterfaceID& interfaceID( ) ;
+    DeclareInterfaceID (IZVTOP_TrkProbTubeCalc, 1, 0);
 
     // declaration of interface-defining member functions
     //trk
-    virtual double calcProbTube(const Trk::Track& trk, Trk::Vertex& vec) = 0;
-    virtual double calcProbTube(const Rec::TrackParticle& trk, Trk::Vertex& vec) = 0;
-    virtual double calcProbTube(const Trk::TrackParticleBase& trk, Trk::Vertex& vec) = 0;
-    virtual double calcProbTube(const Trk::Perigee* trk, Trk::Vertex& vec) = 0;
+    virtual double calcProbTube(const Trk::Track& trk, Trk::Vertex& vec) const = 0;
+    virtual double calcProbTube(const Rec::TrackParticle& trk, Trk::Vertex& vec) const = 0;
+    virtual double calcProbTube(const Trk::TrackParticleBase& trk, Trk::Vertex& vec) const = 0;
+    virtual double calcProbTube(const Trk::Perigee* trk, Trk::Vertex& vec) const = 0;
     //beam spot
-    virtual double calcProbTube(const Trk::RecVertex& vtx, Trk::Vertex& vec) = 0;
+    virtual double calcProbTube(const Trk::RecVertex& vtx, Trk::Vertex& vec) const = 0;
 
   };
 
-  inline const InterfaceID& InDet::IZVTOP_TrkProbTubeCalc::interfaceID()
-    { 
-      return IID_IZVTOP_TrkProbTubeCalc; 
-    }
-
 } // end of namespace
 
 #endif 
diff --git a/InnerDetector/InDetRecTools/InDetZVTOPVxFinder/InDetZVTOPVxFinder/ZVTOP_AmbiguitySolver.h b/InnerDetector/InDetRecTools/InDetZVTOPVxFinder/InDetZVTOPVxFinder/ZVTOP_AmbiguitySolver.h
index 4db855fdf749834cae4a454a7cb111852b89e481..76a78069cf221cd473c9e393fee60821ac04b088 100755
--- a/InnerDetector/InDetRecTools/InDetZVTOPVxFinder/InDetZVTOPVxFinder/ZVTOP_AmbiguitySolver.h
+++ b/InnerDetector/InDetRecTools/InDetZVTOPVxFinder/InDetZVTOPVxFinder/ZVTOP_AmbiguitySolver.h
@@ -1,5 +1,5 @@
 /*
-  Copyright (C) 2002-2017 CERN for the benefit of the ATLAS collaboration
+  Copyright (C) 2002-2019 CERN for the benefit of the ATLAS collaboration
 */
 
 ///////////////////////////////////////////////////////////////////
@@ -34,7 +34,7 @@ namespace InDet
       @author  Tatjana Lenz <tatjana.lenz@cern.ch>
   */  
 
-  class ZVTOP_AmbiguitySolver : virtual public IZVTOP_AmbiguitySolver, public AthAlgTool
+  class ZVTOP_AmbiguitySolver : public extends<AthAlgTool, IZVTOP_AmbiguitySolver>
     {
     public:
       ZVTOP_AmbiguitySolver(const std::string&,const std::string&,const IInterface*);
@@ -43,11 +43,11 @@ namespace InDet
       virtual ~ZVTOP_AmbiguitySolver ();
       
        /** standard Athena-Algorithm method */
-      virtual StatusCode initialize();
+      virtual StatusCode initialize() override;
        /** standard Athena-Algorithm method */
-      virtual StatusCode finalize  ();
+      virtual StatusCode finalize  () override;
       //std::vector<Trk::VxCandidate*> solveAmbiguities(std::vector<Trk::VxCandidate*> VxContainer); --David S.
-      std::vector< xAOD::Vertex* > solveAmbiguities(std::vector< xAOD::Vertex* > VertexContainer);
+      virtual std::vector< xAOD::Vertex* > solveAmbiguities(std::vector< xAOD::Vertex* > VertexContainer) const override;
       
     private:
 
diff --git a/InnerDetector/InDetRecTools/InDetZVTOPVxFinder/InDetZVTOPVxFinder/ZVTOP_SimpleVtxProbCalc.h b/InnerDetector/InDetRecTools/InDetZVTOPVxFinder/InDetZVTOPVxFinder/ZVTOP_SimpleVtxProbCalc.h
index ee4d80f2c91321e54bfc0578e1dbcc3583342b9a..50e0fa05bc24aa3c129a63309405d07d6ca98753 100755
--- a/InnerDetector/InDetRecTools/InDetZVTOPVxFinder/InDetZVTOPVxFinder/ZVTOP_SimpleVtxProbCalc.h
+++ b/InnerDetector/InDetRecTools/InDetZVTOPVxFinder/InDetZVTOPVxFinder/ZVTOP_SimpleVtxProbCalc.h
@@ -1,5 +1,5 @@
 /*
-  Copyright (C) 2002-2017 CERN for the benefit of the ATLAS collaboration
+  Copyright (C) 2002-2019 CERN for the benefit of the ATLAS collaboration
 */
 
 ///////////////////////////////////////////////////////////////////
@@ -21,7 +21,7 @@ namespace InDet
       @author  Tatjana Lenz <tatjana.lenz@cern.ch>
   */  
 
-  class ZVTOP_SimpleVtxProbCalc : virtual public IZVTOP_SimpleVtxProbCalc, public AthAlgTool
+  class ZVTOP_SimpleVtxProbCalc : public extends<AthAlgTool, IZVTOP_SimpleVtxProbCalc>
     {
     public:
       ZVTOP_SimpleVtxProbCalc(const std::string&,const std::string&,const IInterface*);
@@ -30,15 +30,11 @@ namespace InDet
       virtual ~ZVTOP_SimpleVtxProbCalc ();
       
        /** standard Athena-Algorithm method */
-      virtual StatusCode initialize();
+      virtual StatusCode initialize() override;
        /** standard Athena-Algorithm method */
-      virtual StatusCode finalize  ();
-      
-      double calcVtxProb(double & trk_func_sum, double & trk_func_sum2);
-    private:
-
-     
+      virtual StatusCode finalize  () override;
       
+      virtual double calcVtxProb(double & trk_func_sum, double & trk_func_sum2) const override;
     }; 
 } // end of namespace
 
diff --git a/InnerDetector/InDetRecTools/InDetZVTOPVxFinder/InDetZVTOPVxFinder/ZVTOP_SlowSpatialPointFinder.h b/InnerDetector/InDetRecTools/InDetZVTOPVxFinder/InDetZVTOPVxFinder/ZVTOP_SlowSpatialPointFinder.h
index 6e1fbfa88f290fb3e7090f32734a7bf16f10604e..eb7541f7423cf5653a76d2581effaf86e3595407 100644
--- a/InnerDetector/InDetRecTools/InDetZVTOPVxFinder/InDetZVTOPVxFinder/ZVTOP_SlowSpatialPointFinder.h
+++ b/InnerDetector/InDetRecTools/InDetZVTOPVxFinder/InDetZVTOPVxFinder/ZVTOP_SlowSpatialPointFinder.h
@@ -1,5 +1,5 @@
 /*
-  Copyright (C) 2002-2017 CERN for the benefit of the ATLAS collaboration
+  Copyright (C) 2002-2019 CERN for the benefit of the ATLAS collaboration
 */
 
 ///////////////////////////////////////////////////////////////////
@@ -44,7 +44,7 @@ namespace InDet
       @author  Tatjana Lenz <tatjana.lenz@cern.ch>
   */  
 
-  class ZVTOP_SlowSpatialPointFinder : virtual public IZVTOP_SpatialPointFinder, public AthAlgTool
+  class ZVTOP_SlowSpatialPointFinder : public extends<AthAlgTool, IZVTOP_SpatialPointFinder>
     {
     public:
       ZVTOP_SlowSpatialPointFinder(const std::string&,const std::string&,const IInterface*);
@@ -53,18 +53,18 @@ namespace InDet
       virtual ~ZVTOP_SlowSpatialPointFinder ();
       
        /** standard Athena-Algorithm method */
-      virtual StatusCode initialize();
+      virtual StatusCode initialize() override;
        /** standard Athena-Algorithm method */
-      virtual StatusCode finalize  ();
+      virtual StatusCode finalize  () override;
 
-      Trk::Vertex* findSpatialPoint(const Trk::Track* trk_1, const Trk::Track* trk_2);
-      Trk::Vertex* findSpatialPoint(const Trk::RecVertex vtx, const Trk::Track* trk_1);
-      Trk::Vertex* findSpatialPoint(const Rec::TrackParticle* trk_1, const Rec::TrackParticle* trk_2);
-      Trk::Vertex* findSpatialPoint(const Trk::RecVertex vtx, const Rec::TrackParticle* trk_1);
-      Trk::Vertex* findSpatialPoint(const Trk::TrackParticleBase* trk_1, const Trk::TrackParticleBase* trk_2);
-      Trk::Vertex* findSpatialPoint(const Trk::RecVertex vtx, const Trk::TrackParticleBase* trk_1);
-      Trk::Vertex* findSpatialPoint(const Trk::TrackParameters* perigee_1, const Trk::TrackParameters* perigee_2);
-      Trk::Vertex* findSpatialPoint(const Trk::RecVertex vtx, const Trk::TrackParameters* perigee_1);
+      virtual Trk::Vertex* findSpatialPoint(const Trk::Track* trk_1, const Trk::Track* trk_2) const override;
+      virtual Trk::Vertex* findSpatialPoint(const Trk::RecVertex vtx, const Trk::Track* trk_1) const override;
+      virtual Trk::Vertex* findSpatialPoint(const Rec::TrackParticle* trk_1, const Rec::TrackParticle* trk_2) const override;
+      virtual Trk::Vertex* findSpatialPoint(const Trk::RecVertex vtx, const Rec::TrackParticle* trk_1) const override;
+      virtual Trk::Vertex* findSpatialPoint(const Trk::TrackParticleBase* trk_1, const Trk::TrackParticleBase* trk_2) const override;
+      virtual Trk::Vertex* findSpatialPoint(const Trk::RecVertex vtx, const Trk::TrackParticleBase* trk_1) const override;
+      virtual Trk::Vertex* findSpatialPoint(const Trk::TrackParameters* perigee_1, const Trk::TrackParameters* perigee_2) const override;
+      virtual Trk::Vertex* findSpatialPoint(const Trk::RecVertex vtx, const Trk::TrackParameters* perigee_1) const override;
 
     private:
       
diff --git a/InnerDetector/InDetRecTools/InDetZVTOPVxFinder/InDetZVTOPVxFinder/ZVTOP_SpatialPointFinder.h b/InnerDetector/InDetRecTools/InDetZVTOPVxFinder/InDetZVTOPVxFinder/ZVTOP_SpatialPointFinder.h
index 1c8f2f955cbbadcd380f544bf5f530c62f21946b..e54ad926fdc58303ca115e9d84061385263c7b31 100755
--- a/InnerDetector/InDetRecTools/InDetZVTOPVxFinder/InDetZVTOPVxFinder/ZVTOP_SpatialPointFinder.h
+++ b/InnerDetector/InDetRecTools/InDetZVTOPVxFinder/InDetZVTOPVxFinder/ZVTOP_SpatialPointFinder.h
@@ -1,5 +1,5 @@
 /*
-  Copyright (C) 2002-2017 CERN for the benefit of the ATLAS collaboration
+  Copyright (C) 2002-2019 CERN for the benefit of the ATLAS collaboration
 */
 
 ///////////////////////////////////////////////////////////////////
@@ -41,7 +41,7 @@ namespace InDet
       @author  Tatjana Lenz <tatjana.lenz@cern.ch>
   */  
 
-  class ZVTOP_SpatialPointFinder : virtual public IZVTOP_SpatialPointFinder, public AthAlgTool
+  class ZVTOP_SpatialPointFinder : public extends<AthAlgTool, IZVTOP_SpatialPointFinder>
     {
     public:
       ZVTOP_SpatialPointFinder(const std::string&,const std::string&,const IInterface*);
@@ -50,18 +50,18 @@ namespace InDet
       virtual ~ZVTOP_SpatialPointFinder ();
       
        /** standard Athena-Algorithm method */
-      virtual StatusCode initialize();
+      virtual StatusCode initialize() override;
        /** standard Athena-Algorithm method */
-      virtual StatusCode finalize  ();
+      virtual StatusCode finalize  () override;
 
-      Trk::Vertex* findSpatialPoint(const Trk::Track* trk_1, const Trk::Track* trk_2);
-      Trk::Vertex* findSpatialPoint(const Trk::RecVertex vtx, const Trk::Track* trk_1);
-      Trk::Vertex* findSpatialPoint(const Rec::TrackParticle* trk_1, const Rec::TrackParticle* trk_2);
-      Trk::Vertex* findSpatialPoint(const Trk::RecVertex vtx, const Rec::TrackParticle* trk_1);
-      Trk::Vertex* findSpatialPoint(const Trk::TrackParticleBase* trk_1, const Trk::TrackParticleBase* trk_2);
-      Trk::Vertex* findSpatialPoint(const Trk::RecVertex vtx, const Trk::TrackParticleBase* trk_1);
-      Trk::Vertex* findSpatialPoint(const Trk::TrackParameters* perigee_1, const Trk::TrackParameters* perigee_2);
-      Trk::Vertex* findSpatialPoint(const Trk::RecVertex vtx, const Trk::TrackParameters* perigee_1);
+      virtual Trk::Vertex* findSpatialPoint(const Trk::Track* trk_1, const Trk::Track* trk_2) const override;
+      virtual Trk::Vertex* findSpatialPoint(const Trk::RecVertex vtx, const Trk::Track* trk_1) const override;
+      virtual Trk::Vertex* findSpatialPoint(const Rec::TrackParticle* trk_1, const Rec::TrackParticle* trk_2) const override;
+      virtual Trk::Vertex* findSpatialPoint(const Trk::RecVertex vtx, const Rec::TrackParticle* trk_1) const override;
+      virtual Trk::Vertex* findSpatialPoint(const Trk::TrackParticleBase* trk_1, const Trk::TrackParticleBase* trk_2) const override;
+      virtual Trk::Vertex* findSpatialPoint(const Trk::RecVertex vtx, const Trk::TrackParticleBase* trk_1) const override;
+      virtual Trk::Vertex* findSpatialPoint(const Trk::TrackParameters* perigee_1, const Trk::TrackParameters* perigee_2) const override;
+      virtual Trk::Vertex* findSpatialPoint(const Trk::RecVertex vtx, const Trk::TrackParameters* perigee_1) const override;
 
     private:
       double				m_chi2;
diff --git a/InnerDetector/InDetRecTools/InDetZVTOPVxFinder/InDetZVTOPVxFinder/ZVTOP_TrkProbTubeCalc.h b/InnerDetector/InDetRecTools/InDetZVTOPVxFinder/InDetZVTOPVxFinder/ZVTOP_TrkProbTubeCalc.h
index c6910ed5ad8235a943dc7a6e91ea93c502d5b2e9..46c7f67a0a6586400b8e496664d9194323c02cbb 100755
--- a/InnerDetector/InDetRecTools/InDetZVTOPVxFinder/InDetZVTOPVxFinder/ZVTOP_TrkProbTubeCalc.h
+++ b/InnerDetector/InDetRecTools/InDetZVTOPVxFinder/InDetZVTOPVxFinder/ZVTOP_TrkProbTubeCalc.h
@@ -1,5 +1,5 @@
 /*
-  Copyright (C) 2002-2017 CERN for the benefit of the ATLAS collaboration
+  Copyright (C) 2002-2019 CERN for the benefit of the ATLAS collaboration
 */
 
 ///////////////////////////////////////////////////////////////////
@@ -30,7 +30,7 @@ namespace InDet
       @author  Tatjana Lenz <tatjana.lenz@cern.ch>
   */  
 
-  class ZVTOP_TrkProbTubeCalc : virtual public IZVTOP_TrkProbTubeCalc, public AthAlgTool
+  class ZVTOP_TrkProbTubeCalc : public extends<AthAlgTool, IZVTOP_TrkProbTubeCalc>
     {
     public:
       ZVTOP_TrkProbTubeCalc(const std::string&,const std::string&,const IInterface*);
@@ -39,15 +39,15 @@ namespace InDet
       virtual ~ZVTOP_TrkProbTubeCalc ();
       
        /** standard Athena-Algorithm method */
-      virtual StatusCode initialize();
+      virtual StatusCode initialize() override;
        /** standard Athena-Algorithm method */
-      virtual StatusCode finalize  ();
+      virtual StatusCode finalize  () override;
       
-      virtual double calcProbTube(const Trk::Track& trk, Trk::Vertex& vec);
-      virtual double calcProbTube(const Rec::TrackParticle& trk, Trk::Vertex& vec);
-      virtual double calcProbTube(const Trk::TrackParticleBase& trk, Trk::Vertex& vec);
-      virtual double calcProbTube(const Trk::Perigee* trk, Trk::Vertex& vec);
-      virtual double calcProbTube(const Trk::RecVertex& vtx, Trk::Vertex& vec);
+      virtual double calcProbTube(const Trk::Track& trk, Trk::Vertex& vec) const override;
+      virtual double calcProbTube(const Rec::TrackParticle& trk, Trk::Vertex& vec) const override;
+      virtual double calcProbTube(const Trk::TrackParticleBase& trk, Trk::Vertex& vec) const override;
+      virtual double calcProbTube(const Trk::Perigee* trk, Trk::Vertex& vec) const override;
+      virtual double calcProbTube(const Trk::RecVertex& vtx, Trk::Vertex& vec) const override;
     private:
       
       /** member variables for algorithm properties: */
diff --git a/InnerDetector/InDetRecTools/InDetZVTOPVxFinder/src/ZVTOP_AmbiguitySolver.cxx b/InnerDetector/InDetRecTools/InDetZVTOPVxFinder/src/ZVTOP_AmbiguitySolver.cxx
index 86403b1f88cf7a550b0eab0e3400489026611199..9c82d40b6f338aa86a6a8c871178bf523d794b7d 100755
--- a/InnerDetector/InDetRecTools/InDetZVTOPVxFinder/src/ZVTOP_AmbiguitySolver.cxx
+++ b/InnerDetector/InDetRecTools/InDetZVTOPVxFinder/src/ZVTOP_AmbiguitySolver.cxx
@@ -1,5 +1,5 @@
 /*
-  Copyright (C) 2002-2017 CERN for the benefit of the ATLAS collaboration
+  Copyright (C) 2002-2019 CERN for the benefit of the ATLAS collaboration
 */
 
 ///////////////////////////////////////////////////////////////////
@@ -21,12 +21,10 @@ InDet::ZVTOP_AmbiguitySolver::ZVTOP_AmbiguitySolver(const std::string& t,
 			  const std::string& n,
 			  const IInterface*  p )
   :
-  AthAlgTool(t,n,p),
+  base_class(t,n,p),
   m_TrkProbTubeCalc("InDet::ZVTOP_TrkProbTubeCalc"),
   m_VtxProbCalc("InDet::ZVTOP_VtxProbCalc")
 {
-  declareInterface<IZVTOP_AmbiguitySolver>(this);
-
   //  template for property decalration
   declareProperty("TrkProbTubeCalcTool",m_TrkProbTubeCalc);
   declareProperty("VtxProbCalcTool",m_VtxProbCalc);
@@ -50,7 +48,7 @@ StatusCode InDet::ZVTOP_AmbiguitySolver::initialize()
   return StatusCode::SUCCESS;
 }
 
-std::vector<xAOD::Vertex*> InDet::ZVTOP_AmbiguitySolver::solveAmbiguities(std::vector<xAOD::Vertex*> VertexContainer)
+std::vector<xAOD::Vertex*> InDet::ZVTOP_AmbiguitySolver::solveAmbiguities(std::vector<xAOD::Vertex*> VertexContainer) const
 {
   std::vector<xAOD::Vertex*> newVertexContainer;
   std::vector<xAOD::Vertex*>::iterator itr = VertexContainer.begin();
diff --git a/InnerDetector/InDetRecTools/InDetZVTOPVxFinder/src/ZVTOP_SimpleVtxProbCalc.cxx b/InnerDetector/InDetRecTools/InDetZVTOPVxFinder/src/ZVTOP_SimpleVtxProbCalc.cxx
index 66c2c238aaa5057a933735b9001a2b4b2844ec2d..272566468230d2a4d46582183b4cabbbd2111c58 100755
--- a/InnerDetector/InDetRecTools/InDetZVTOPVxFinder/src/ZVTOP_SimpleVtxProbCalc.cxx
+++ b/InnerDetector/InDetRecTools/InDetZVTOPVxFinder/src/ZVTOP_SimpleVtxProbCalc.cxx
@@ -1,5 +1,5 @@
 /*
-  Copyright (C) 2002-2017 CERN for the benefit of the ATLAS collaboration
+  Copyright (C) 2002-2019 CERN for the benefit of the ATLAS collaboration
 */
 
 ///////////////////////////////////////////////////////////////////
@@ -14,10 +14,8 @@ InDet::ZVTOP_SimpleVtxProbCalc::ZVTOP_SimpleVtxProbCalc(const std::string& t,
 			  const std::string& n,
 			  const IInterface*  p )
   :
-  AthAlgTool(t,n,p)
+  base_class(t,n,p)
 {
-  declareInterface<IZVTOP_SimpleVtxProbCalc>(this);
-
   //  template for property decalration
   //declareProperty("PropertyName", m_propertyName);
 }
@@ -32,12 +30,8 @@ InDet::ZVTOP_SimpleVtxProbCalc::~ZVTOP_SimpleVtxProbCalc()
 
 StatusCode InDet::ZVTOP_SimpleVtxProbCalc::initialize()
 {
-  
-  StatusCode sc = AlgTool::initialize();
-
-  if (sc.isFailure()) return sc;
-
-  msg (MSG::INFO) << "initialize() successful in " << name() << endmsg;
+  ATH_CHECK( AlgTool::initialize() );
+  ATH_MSG_INFO ( "initialize() successful in " << name() );
   return StatusCode::SUCCESS;
 }
 
@@ -45,12 +39,11 @@ StatusCode InDet::ZVTOP_SimpleVtxProbCalc::initialize()
 
 StatusCode InDet::ZVTOP_SimpleVtxProbCalc::finalize()
 {
-  StatusCode sc = AlgTool::finalize();
-  return sc;
+  return AlgTool::finalize();
 }
 
 //============================================================================================
-double InDet::ZVTOP_SimpleVtxProbCalc::calcVtxProb(double & trk_func_sum, double & trk_func_sum2)
+double InDet::ZVTOP_SimpleVtxProbCalc::calcVtxProb(double & trk_func_sum, double & trk_func_sum2) const
 {
   double vtx_prob = 0.;
   if (trk_func_sum != 0.) vtx_prob = trk_func_sum - trk_func_sum2/trk_func_sum;
diff --git a/InnerDetector/InDetRecTools/InDetZVTOPVxFinder/src/ZVTOP_SlowSpatialPointFinder.cxx b/InnerDetector/InDetRecTools/InDetZVTOPVxFinder/src/ZVTOP_SlowSpatialPointFinder.cxx
index 90339dc5c39296882234c51669ce2fed07871a5e..feae800003932dee3925606b52f1d8bfe987cd95 100644
--- a/InnerDetector/InDetRecTools/InDetZVTOPVxFinder/src/ZVTOP_SlowSpatialPointFinder.cxx
+++ b/InnerDetector/InDetRecTools/InDetZVTOPVxFinder/src/ZVTOP_SlowSpatialPointFinder.cxx
@@ -1,5 +1,5 @@
 /*
-  Copyright (C) 2002-2017 CERN for the benefit of the ATLAS collaboration
+  Copyright (C) 2002-2019 CERN for the benefit of the ATLAS collaboration
 */
 
 ///////////////////////////////////////////////////////////////////
@@ -18,9 +18,8 @@
 
 InDet::ZVTOP_SlowSpatialPointFinder::ZVTOP_SlowSpatialPointFinder(const std::string& t, const std::string& n, const IInterface*  p )
   :
-  AthAlgTool(t,n,p)
+  base_class(t,n,p)
 {
-  declareInterface<IZVTOP_SpatialPointFinder>(this);
   //  template for property declaration
   declareProperty("Chi2_cut_value", m_chi2);
   declareProperty ( "LinearizedTrackFactory", m_linFactory );
@@ -59,7 +58,7 @@ StatusCode InDet::ZVTOP_SlowSpatialPointFinder::finalize()
   return sc;
 }
 //============================================================================================
-Trk::Vertex* InDet::ZVTOP_SlowSpatialPointFinder::findSpatialPoint(const Trk::Track* trk_1, const Trk::Track* trk_2)
+Trk::Vertex* InDet::ZVTOP_SlowSpatialPointFinder::findSpatialPoint(const Trk::Track* trk_1, const Trk::Track* trk_2) const
 {
   const Trk::TrackParameters* perigee_1(dynamic_cast<const Trk::TrackParameters*>(trk_1->perigeeParameters()));
   const Trk::TrackParameters* perigee_2(dynamic_cast<const Trk::TrackParameters*>(trk_2->perigeeParameters()));
@@ -74,7 +73,7 @@ Trk::Vertex* InDet::ZVTOP_SlowSpatialPointFinder::findSpatialPoint(const Trk::Tr
 
 //============================================================================================
 
-Trk::Vertex* InDet::ZVTOP_SlowSpatialPointFinder::findSpatialPoint(const Trk::RecVertex vtx, const Trk::Track* trk_1)
+Trk::Vertex* InDet::ZVTOP_SlowSpatialPointFinder::findSpatialPoint(const Trk::RecVertex vtx, const Trk::Track* trk_1) const
 {
   const Trk::TrackParameters *perigee_1(dynamic_cast<const Trk::TrackParameters*>(trk_1->perigeeParameters()));
   if (!perigee_1) {
@@ -88,7 +87,7 @@ Trk::Vertex* InDet::ZVTOP_SlowSpatialPointFinder::findSpatialPoint(const Trk::Re
 }
 
 //============================================================================================
-Trk::Vertex* InDet::ZVTOP_SlowSpatialPointFinder::findSpatialPoint(const Rec::TrackParticle* trk_1, const Rec::TrackParticle* trk_2)
+Trk::Vertex* InDet::ZVTOP_SlowSpatialPointFinder::findSpatialPoint(const Rec::TrackParticle* trk_1, const Rec::TrackParticle* trk_2) const
 {
   const Trk::TrackParameters* perigee_1(trk_1->measuredPerigee());
   const Trk::TrackParameters* perigee_2(trk_2->measuredPerigee());
@@ -103,7 +102,7 @@ Trk::Vertex* InDet::ZVTOP_SlowSpatialPointFinder::findSpatialPoint(const Rec::Tr
 }
 
 //============================================================================================
-Trk::Vertex* InDet::ZVTOP_SlowSpatialPointFinder::findSpatialPoint(const Trk::RecVertex vtx, const Rec::TrackParticle* trk_1)
+Trk::Vertex* InDet::ZVTOP_SlowSpatialPointFinder::findSpatialPoint(const Trk::RecVertex vtx, const Rec::TrackParticle* trk_1) const
 {
   const Trk::TrackParameters* perigee_1(trk_1->measuredPerigee());
   if (!perigee_1) {
@@ -116,7 +115,7 @@ Trk::Vertex* InDet::ZVTOP_SlowSpatialPointFinder::findSpatialPoint(const Trk::Re
 }
 
 //============================================================================================
-Trk::Vertex* InDet::ZVTOP_SlowSpatialPointFinder::findSpatialPoint(const Trk::TrackParticleBase* trk_1, const Trk::TrackParticleBase* trk_2)
+Trk::Vertex* InDet::ZVTOP_SlowSpatialPointFinder::findSpatialPoint(const Trk::TrackParticleBase* trk_1, const Trk::TrackParticleBase* trk_2) const
 {
   const Trk::TrackParameters* perigee_1 = dynamic_cast<const Trk::TrackParameters*>(&(trk_1)->definingParameters());
   const Trk::TrackParameters* perigee_2 = dynamic_cast<const Trk::TrackParameters*>(&(trk_2)->definingParameters());
@@ -130,7 +129,7 @@ Trk::Vertex* InDet::ZVTOP_SlowSpatialPointFinder::findSpatialPoint(const Trk::Tr
   }//if measured perigee
 }
 //============================================================================================
-Trk::Vertex* InDet::ZVTOP_SlowSpatialPointFinder::findSpatialPoint(const Trk::RecVertex vtx, const Trk::TrackParticleBase* trk_1)
+Trk::Vertex* InDet::ZVTOP_SlowSpatialPointFinder::findSpatialPoint(const Trk::RecVertex vtx, const Trk::TrackParticleBase* trk_1) const
 {
   const Trk::TrackParameters* perigee_1 = dynamic_cast<const Trk::TrackParameters*>(&(trk_1)->definingParameters());
   if (!perigee_1) {
@@ -144,7 +143,7 @@ Trk::Vertex* InDet::ZVTOP_SlowSpatialPointFinder::findSpatialPoint(const Trk::Re
 
 //=============================================================================================
 
-Trk::Vertex* InDet::ZVTOP_SlowSpatialPointFinder::findSpatialPoint(const Trk::TrackParameters* perigee_1, const Trk::TrackParameters* perigee_2)
+Trk::Vertex* InDet::ZVTOP_SlowSpatialPointFinder::findSpatialPoint(const Trk::TrackParameters* perigee_1, const Trk::TrackParameters* perigee_2) const
 {
   Amg::Vector3D spatialPoint;
   //we need Trk::Vertex
@@ -204,7 +203,7 @@ Trk::Vertex* InDet::ZVTOP_SlowSpatialPointFinder::findSpatialPoint(const Trk::Tr
 }
 
 //========================================================================================================
-Trk::Vertex* InDet::ZVTOP_SlowSpatialPointFinder::findSpatialPoint(const Trk::RecVertex vtx, const Trk::TrackParameters* perigee_1)
+Trk::Vertex* InDet::ZVTOP_SlowSpatialPointFinder::findSpatialPoint(const Trk::RecVertex vtx, const Trk::TrackParameters* perigee_1) const
 {
   Amg::Vector3D spatialPoint;
   //we need Trk::Vertex
diff --git a/InnerDetector/InDetRecTools/InDetZVTOPVxFinder/src/ZVTOP_SpatialPointFinder.cxx b/InnerDetector/InDetRecTools/InDetZVTOPVxFinder/src/ZVTOP_SpatialPointFinder.cxx
index e7fdd86fcc1cd7f65cfc0737ce3ab95c91e557c6..7805cdb4bf1419ffab2fea6360530ffff2818f41 100755
--- a/InnerDetector/InDetRecTools/InDetZVTOPVxFinder/src/ZVTOP_SpatialPointFinder.cxx
+++ b/InnerDetector/InDetRecTools/InDetZVTOPVxFinder/src/ZVTOP_SpatialPointFinder.cxx
@@ -1,5 +1,5 @@
 /*
-  Copyright (C) 2002-2017 CERN for the benefit of the ATLAS collaboration
+  Copyright (C) 2002-2019 CERN for the benefit of the ATLAS collaboration
 */
 
 ///////////////////////////////////////////////////////////////////
@@ -19,10 +19,8 @@ InDet::ZVTOP_SpatialPointFinder::ZVTOP_SpatialPointFinder(const std::string& t,
 			  const std::string& n,
 			  const IInterface*  p )
   :
-  AthAlgTool(t,n,p)
+  base_class(t,n,p)
 {
-  declareInterface<IZVTOP_SpatialPointFinder>(this);
-
   //  template for property declaration
   declareProperty("Chi2_cut_value", m_chi2);
 }
@@ -48,7 +46,7 @@ StatusCode InDet::ZVTOP_SpatialPointFinder::finalize()
   return StatusCode::SUCCESS;
 }
 //============================================================================================
-Trk::Vertex* InDet::ZVTOP_SpatialPointFinder::findSpatialPoint(const Trk::Track* trk_1, const Trk::Track* trk_2)
+Trk::Vertex* InDet::ZVTOP_SpatialPointFinder::findSpatialPoint(const Trk::Track* trk_1, const Trk::Track* trk_2) const
 {
   const Trk::TrackParameters* perigee_1(dynamic_cast<const Trk::TrackParameters*>(trk_1->perigeeParameters()));
   const Trk::TrackParameters* perigee_2(dynamic_cast<const Trk::TrackParameters*>(trk_2->perigeeParameters()));
@@ -62,7 +60,7 @@ Trk::Vertex* InDet::ZVTOP_SpatialPointFinder::findSpatialPoint(const Trk::Track*
 }
 
 //===============================================================================================
-Trk::Vertex* InDet::ZVTOP_SpatialPointFinder::findSpatialPoint(const Trk::RecVertex vtx, const Trk::Track* trk_1)
+Trk::Vertex* InDet::ZVTOP_SpatialPointFinder::findSpatialPoint(const Trk::RecVertex vtx, const Trk::Track* trk_1) const
 {
   const Trk::TrackParameters *perigee_1(dynamic_cast<const Trk::TrackParameters*>(trk_1->perigeeParameters()));
   if (!perigee_1) {
@@ -75,7 +73,7 @@ Trk::Vertex* InDet::ZVTOP_SpatialPointFinder::findSpatialPoint(const Trk::RecVer
 }
 
 //============================================================================================
-Trk::Vertex* InDet::ZVTOP_SpatialPointFinder::findSpatialPoint(const Rec::TrackParticle* trk_1, const Rec::TrackParticle* trk_2)
+Trk::Vertex* InDet::ZVTOP_SpatialPointFinder::findSpatialPoint(const Rec::TrackParticle* trk_1, const Rec::TrackParticle* trk_2) const
 {
   const Trk::TrackParameters* perigee_1(trk_1->measuredPerigee());
   const Trk::TrackParameters* perigee_2(trk_2->measuredPerigee());
@@ -89,7 +87,7 @@ Trk::Vertex* InDet::ZVTOP_SpatialPointFinder::findSpatialPoint(const Rec::TrackP
 }
 
 //============================================================================================
-Trk::Vertex* InDet::ZVTOP_SpatialPointFinder::findSpatialPoint(const Trk::RecVertex vtx, const Rec::TrackParticle* trk_1)
+Trk::Vertex* InDet::ZVTOP_SpatialPointFinder::findSpatialPoint(const Trk::RecVertex vtx, const Rec::TrackParticle* trk_1) const
 {
   const Trk::TrackParameters* perigee_1(trk_1->measuredPerigee());
   if (!perigee_1) {
@@ -101,7 +99,7 @@ Trk::Vertex* InDet::ZVTOP_SpatialPointFinder::findSpatialPoint(const Trk::RecVer
   }
 }
 //============================================================================================
-Trk::Vertex* InDet::ZVTOP_SpatialPointFinder::findSpatialPoint(const Trk::TrackParticleBase* trk_1, const Trk::TrackParticleBase* trk_2)
+Trk::Vertex* InDet::ZVTOP_SpatialPointFinder::findSpatialPoint(const Trk::TrackParticleBase* trk_1, const Trk::TrackParticleBase* trk_2) const
 {
   const Trk::TrackParameters* perigee_1 = dynamic_cast<const Trk::TrackParameters*>(&trk_1->definingParameters());
   const Trk::TrackParameters* perigee_2 = dynamic_cast<const Trk::TrackParameters*>(&trk_2->definingParameters());
@@ -115,7 +113,7 @@ Trk::Vertex* InDet::ZVTOP_SpatialPointFinder::findSpatialPoint(const Trk::TrackP
 }
 
 //============================================================================================
-Trk::Vertex* InDet::ZVTOP_SpatialPointFinder::findSpatialPoint(const Trk::RecVertex vtx, const Trk::TrackParticleBase* trk_1)
+Trk::Vertex* InDet::ZVTOP_SpatialPointFinder::findSpatialPoint(const Trk::RecVertex vtx, const Trk::TrackParticleBase* trk_1) const
 {
   const Trk::TrackParameters* perigee_1 = dynamic_cast<const Trk::TrackParameters*>(&trk_1->definingParameters());
   if (!perigee_1) {
@@ -130,7 +128,7 @@ Trk::Vertex* InDet::ZVTOP_SpatialPointFinder::findSpatialPoint(const Trk::RecVer
 //===============================================================================================
 
 
-Trk::Vertex* InDet::ZVTOP_SpatialPointFinder::findSpatialPoint(const Trk::TrackParameters* param_1, const Trk::TrackParameters* param_2)
+Trk::Vertex* InDet::ZVTOP_SpatialPointFinder::findSpatialPoint(const Trk::TrackParameters* param_1, const Trk::TrackParameters* param_2) const
 {
   Amg::Vector3D spatialPoint;
   const Trk::Perigee* perigee_1 =dynamic_cast<const Trk::Perigee*>(param_1);
@@ -202,7 +200,7 @@ Trk::Vertex* InDet::ZVTOP_SpatialPointFinder::findSpatialPoint(const Trk::TrackP
 
 //============================================================================================
 
-Trk::Vertex* InDet::ZVTOP_SpatialPointFinder::findSpatialPoint(const Trk::RecVertex vtx, const Trk::TrackParameters* param_1)
+Trk::Vertex* InDet::ZVTOP_SpatialPointFinder::findSpatialPoint(const Trk::RecVertex vtx, const Trk::TrackParameters* param_1) const
 {
   Amg::Vector3D spatialPoint;
   const Trk::Perigee* perigee_1 =dynamic_cast<const Trk::Perigee*>(param_1);
diff --git a/InnerDetector/InDetRecTools/InDetZVTOPVxFinder/src/ZVTOP_TrkProbTubeCalc.cxx b/InnerDetector/InDetRecTools/InDetZVTOPVxFinder/src/ZVTOP_TrkProbTubeCalc.cxx
index 269b91481223d3544d411524cd57abda4bd86689..486931a1e22545d1ecca595bce2eed238e55a40a 100755
--- a/InnerDetector/InDetRecTools/InDetZVTOPVxFinder/src/ZVTOP_TrkProbTubeCalc.cxx
+++ b/InnerDetector/InDetRecTools/InDetZVTOPVxFinder/src/ZVTOP_TrkProbTubeCalc.cxx
@@ -1,5 +1,5 @@
 /*
-  Copyright (C) 2002-2017 CERN for the benefit of the ATLAS collaboration
+  Copyright (C) 2002-2019 CERN for the benefit of the ATLAS collaboration
 */
 
 ///////////////////////////////////////////////////////////////////
@@ -22,9 +22,8 @@ InDet::ZVTOP_TrkProbTubeCalc::ZVTOP_TrkProbTubeCalc(const std::string& t,
 			  const std::string& n,
 			  const IInterface*  p )
   :
-  AthAlgTool(t,n,p)
+  base_class(t,n,p)
 {
-  declareInterface<IZVTOP_TrkProbTubeCalc>(this);
   //  template for property declaration
   declareProperty("Extrapolator",		m_extrapolator);
 }
@@ -53,7 +52,7 @@ StatusCode InDet::ZVTOP_TrkProbTubeCalc::finalize()
 }
 
 //============================================================================================
-double InDet::ZVTOP_TrkProbTubeCalc::calcProbTube(const Trk::Track& trk, Trk::Vertex& vec)
+double InDet::ZVTOP_TrkProbTubeCalc::calcProbTube(const Trk::Track& trk, Trk::Vertex& vec) const
 {
   double probTube = 0.;
   //perigee surface 
@@ -64,7 +63,7 @@ double InDet::ZVTOP_TrkProbTubeCalc::calcProbTube(const Trk::Track& trk, Trk::Ve
 }
 
 //============================================================================================
-double InDet::ZVTOP_TrkProbTubeCalc::calcProbTube(const Trk::RecVertex& beam_spot, Trk::Vertex& vec)
+double InDet::ZVTOP_TrkProbTubeCalc::calcProbTube(const Trk::RecVertex& beam_spot, Trk::Vertex& vec) const
 {
   double probTube = 0.;
   Amg::Vector3D diff; 
@@ -76,7 +75,7 @@ double InDet::ZVTOP_TrkProbTubeCalc::calcProbTube(const Trk::RecVertex& beam_spo
   return probTube;
 }
 //============================================================================================
-double InDet::ZVTOP_TrkProbTubeCalc::calcProbTube(const Rec::TrackParticle& trk, Trk::Vertex& vec)
+double InDet::ZVTOP_TrkProbTubeCalc::calcProbTube(const Rec::TrackParticle& trk, Trk::Vertex& vec) const
 {
   double probTube = 0.;
   const Trk::Perigee* trkPer(trk.measuredPerigee());
@@ -84,7 +83,7 @@ double InDet::ZVTOP_TrkProbTubeCalc::calcProbTube(const Rec::TrackParticle& trk,
   return probTube;
 }
 
-double InDet::ZVTOP_TrkProbTubeCalc::calcProbTube(const Trk::TrackParticleBase& trk, Trk::Vertex& vec)
+double InDet::ZVTOP_TrkProbTubeCalc::calcProbTube(const Trk::TrackParticleBase& trk, Trk::Vertex& vec) const
 {
   double probTube = 0.;
   //perigee surface 
@@ -94,7 +93,7 @@ double InDet::ZVTOP_TrkProbTubeCalc::calcProbTube(const Trk::TrackParticleBase&
   return probTube;
 }
 
-double InDet::ZVTOP_TrkProbTubeCalc::calcProbTube(const Trk::Perigee* trkPer, Trk::Vertex& vec){
+double InDet::ZVTOP_TrkProbTubeCalc::calcProbTube(const Trk::Perigee* trkPer, Trk::Vertex& vec) const {
 
   double probTube = 0.;
   Amg::Vector3D lp =vec.position();