diff --git a/DataFormats/FWLite/src/Event.cc b/DataFormats/FWLite/src/Event.cc
index 86690245ca7de..062e403759621 100644
--- a/DataFormats/FWLite/src/Event.cc
+++ b/DataFormats/FWLite/src/Event.cc
@@ -347,9 +347,8 @@ Event::history() const {
         TBranch* b = meta->GetBranch(edm::poolNames::processHistoryBranchName().c_str());
         b->SetAddress(&pPhv);
         b->GetEntry(0);
-        for (edm::ProcessHistoryVector::const_iterator i = historyVector.begin(), e = historyVector.end();
-            i != e; ++i) {
-          historyMap_.insert(std::make_pair(i->id(), *i));
+        for (auto& history : historyVector) {
+          historyMap_.insert(std::make_pair(history.setProcessHistoryID(), history));
         }
       }
     }
diff --git a/DataFormats/FWLite/src/LuminosityBlock.cc b/DataFormats/FWLite/src/LuminosityBlock.cc
index 626da9d53e220..63451440d59b1 100644
--- a/DataFormats/FWLite/src/LuminosityBlock.cc
+++ b/DataFormats/FWLite/src/LuminosityBlock.cc
@@ -298,9 +298,8 @@ LuminosityBlock::history() const
         TBranch* b = meta->GetBranch(edm::poolNames::processHistoryBranchName().c_str());
         b->SetAddress(&pPhv);
         b->GetEntry(0);
-        for (edm::ProcessHistoryVector::const_iterator i = historyVector.begin(), e = historyVector.end();
-            i != e; ++i) {
-          historyMap_.insert(std::make_pair(i->id(), *i));
+        for (auto& history : historyVector) {
+          historyMap_.insert(std::make_pair(history.setProcessHistoryID(), history));
         }
       }
     }
diff --git a/DataFormats/FWLite/src/Run.cc b/DataFormats/FWLite/src/Run.cc
index 37ae3bea1d540..e43dc2bee5911 100644
--- a/DataFormats/FWLite/src/Run.cc
+++ b/DataFormats/FWLite/src/Run.cc
@@ -295,9 +295,8 @@ Run::history() const
         TBranch* b = meta->GetBranch(edm::poolNames::processHistoryBranchName().c_str());
         b->SetAddress(&pPhv);
         b->GetEntry(0);
-        for (edm::ProcessHistoryVector::const_iterator i = historyVector.begin(), e = historyVector.end();
-            i != e; ++i) {
-          historyMap_.insert(std::make_pair(i->id(), *i));
+        for (auto& history : historyVector) {
+          historyMap_.insert(std::make_pair(history.setProcessHistoryID(), history));
         }
       }
     }
diff --git a/DataFormats/Provenance/interface/EventEntryDescription.h b/DataFormats/Provenance/interface/EventEntryDescription.h
index 0fa98c97c39ec..02680e659b0fe 100644
--- a/DataFormats/Provenance/interface/EventEntryDescription.h
+++ b/DataFormats/Provenance/interface/EventEntryDescription.h
@@ -37,7 +37,8 @@ namespace edm {
     void write(std::ostream& os) const;
 
     std::vector<BranchID> const& parents() const {return parents_;}
-    std::vector<BranchID> & parents() {return parents_;}
+    
+    void setParents(std::vector<BranchID> const& parents) {parents_ = parents;} 
 
   private:
 
diff --git a/DataFormats/Provenance/interface/Parentage.h b/DataFormats/Provenance/interface/Parentage.h
index 212b681f32fa2..6bdb51322f5d0 100644
--- a/DataFormats/Provenance/interface/Parentage.h
+++ b/DataFormats/Provenance/interface/Parentage.h
@@ -30,30 +30,24 @@ namespace edm {
 
     ~Parentage() {}
 
-    // Only the 'salient attributes' are encoded into the ID.
     ParentageID id() const;
 
     void write(std::ostream& os) const;
 
     std::vector<BranchID> const& parents() const {return parents_;}
-    std::vector<BranchID> & parents() {return parents_;}
-    void swap(Parentage& other) {parents_.swap(other.parents_); parentageID().swap(other.parentageID());}
-
+    std::vector<BranchID>& parentsForUpdate() {return parents_;}
+    void setParents(std::vector<BranchID> const& parents) {parents_ = parents;}
+    void swap(Parentage& other) {parents_.swap(other.parents_);}
     void initializeTransients() {transient_.reset();}
-
     struct Transients {
-      Transients() : parentageID_() {}
-      void reset() {parentageID_.reset();}
-      mutable ParentageID parentageID_;
+      Transients() {}
+      void reset() {}
     };
 
-
   private:
-    ParentageID& parentageID() const {return transient_.parentageID_;}
     // The Branch IDs of the parents
     std::vector<BranchID> parents_;
     Transients transient_;
-
   };
 
   // Free swap function
diff --git a/DataFormats/Provenance/interface/ProcessConfiguration.h b/DataFormats/Provenance/interface/ProcessConfiguration.h
index 3c58712b6067c..d4c6b3c16f1c7 100644
--- a/DataFormats/Provenance/interface/ProcessConfiguration.h
+++ b/DataFormats/Provenance/interface/ProcessConfiguration.h
@@ -31,6 +31,8 @@ namespace edm {
 
     void setParameterSetID(ParameterSetID const& pSetID);
 
+    ProcessConfigurationID setProcessConfigurationID();
+
     void reduce();
 
     void initializeTransients() {transient_.reset();}
@@ -42,12 +44,11 @@ namespace edm {
         pcid_.reset();
         isCurrentProcess_ = false;
       }
-      mutable ProcessConfigurationID pcid_;
+      ProcessConfigurationID pcid_;
       bool isCurrentProcess_;
     };
 
   private:
-    ProcessConfigurationID const& pcid() const {return transient_.pcid_;}
     void setPCID(ProcessConfigurationID const& pcid) {transient_.pcid_ = pcid;}
     bool isCurrentProcess() const {return transient_.isCurrentProcess_;}
     void setCurrentProcess() {transient_.isCurrentProcess_ = true;}
diff --git a/DataFormats/Provenance/interface/ProcessHistory.h b/DataFormats/Provenance/interface/ProcessHistory.h
index 6482ed02bb120..b7d2ee4c6baa6 100644
--- a/DataFormats/Provenance/interface/ProcessHistory.h
+++ b/DataFormats/Provenance/interface/ProcessHistory.h
@@ -63,6 +63,7 @@ namespace edm {
 
     collection_type const& data() const {return data_;}
     ProcessHistoryID id() const;
+    ProcessHistoryID setProcessHistoryID();
 
     // Return true, and fill in config appropriately, if the a process
     // with the given name is recorded in this ProcessHistory. Return
@@ -82,11 +83,11 @@ namespace edm {
     struct Transients {
       Transients() : phid_() {}
       void reset() {phid_.reset();}
-      mutable ProcessHistoryID phid_;
+      ProcessHistoryID phid_;
     };
 
   private:
-    ProcessHistoryID& phid() const {return transient_.phid_;}
+    ProcessHistoryID& phid() {return transient_.phid_;}
     collection_type data_;
     Transients transient_;
   };
diff --git a/DataFormats/Provenance/src/FullHistoryToReducedHistoryMap.cc b/DataFormats/Provenance/src/FullHistoryToReducedHistoryMap.cc
index bbb7455b930ce..2d078162cfd22 100644
--- a/DataFormats/Provenance/src/FullHistoryToReducedHistoryMap.cc
+++ b/DataFormats/Provenance/src/FullHistoryToReducedHistoryMap.cc
@@ -14,6 +14,7 @@ namespace edm {
     // ProcessHistoryID is strangely also defined as the ID of the empty
     // Process History (maybe that should be fixed ...).
     ProcessHistory ph;
+    ph.setProcessHistoryID();
     std::pair<ProcessHistoryID, ProcessHistoryID> newEntry(ph.id(), ph.id());
     std::pair<Map::iterator, bool> result = cache_.insert(newEntry);
     previous_ = result.first;
@@ -36,7 +37,7 @@ namespace edm {
         << "Contact a Framework developer\n";
     }
     ph.reduce();
-    std::pair<ProcessHistoryID, ProcessHistoryID> newEntry(fullID, ph.id());
+    std::pair<ProcessHistoryID, ProcessHistoryID> newEntry(fullID, ph.setProcessHistoryID());
     std::pair<Map::iterator, bool> result = cache_.insert(newEntry);
     previous_ = result.first;
     return result.first->second;
diff --git a/DataFormats/Provenance/src/Parentage.cc b/DataFormats/Provenance/src/Parentage.cc
index 5af9d78165550..26ad9aad06fe2 100644
--- a/DataFormats/Provenance/src/Parentage.cc
+++ b/DataFormats/Provenance/src/Parentage.cc
@@ -8,35 +8,24 @@
 ----------------------------------------------------------------------*/
 
 namespace edm {
-  Parentage::Parentage() :
-    parents_()
-  {}
+  Parentage::Parentage() : parents_() {
+  }
 
   Parentage::Parentage(std::vector<BranchID> const& parents) :
-    parents_(parents)
-  {}
+    parents_(parents) {
+  }
 
   ParentageID
   Parentage::id() const {
-    // This implementation is ripe for optimization.
-    if(parentageID().isValid()) {
-      return parentageID();
-    }
     std::ostringstream oss;
-    for (std::vector<BranchID>::const_iterator 
-	   i = parents_.begin(),
-	   e = parents_.end();
-	 i != e;
-	 ++i)
-      {
-	oss << *i << ' ';
-      }
+    for (auto const& parent : parents_) {
+      oss << parent << ' ';
+    }
     
     std::string stringrep = oss.str();
     cms::Digest md5alg(stringrep);
-    ParentageID tmp(md5alg.digest().toString());
-    parentageID().swap(tmp);
-    return parentageID();
+    ParentageID id(md5alg.digest().toString());
+    return id;
   }
 
   void
@@ -47,7 +36,6 @@ namespace edm {
     
   bool
   operator==(Parentage const& a, Parentage const& b) {
-    return
-      a.parents() == b.parents();
+    return a.parents() == b.parents();
   }
 }
diff --git a/DataFormats/Provenance/src/ProcessConfiguration.cc b/DataFormats/Provenance/src/ProcessConfiguration.cc
index c38224b7e49a8..33022b37d866b 100644
--- a/DataFormats/Provenance/src/ProcessConfiguration.cc
+++ b/DataFormats/Provenance/src/ProcessConfiguration.cc
@@ -52,17 +52,16 @@ namespace edm {
 
   ProcessConfigurationID
   ProcessConfiguration::id() const {
-    if(pcid().isValid()) {
-      return pcid();
+    if(transient_.pcid_.isValid()) {
+      return transient_.pcid_; 
     }
     // This implementation is ripe for optimization.
     std::ostringstream oss;
     oss << *this;
     std::string stringrep = oss.str();
     cms::Digest md5alg(stringrep);
-    ProcessConfigurationID tmp(md5alg.digest().toString());
-    transient_.pcid_.swap(tmp);
-    return pcid();
+    ProcessConfigurationID pcid(md5alg.digest().toString());
+    return pcid;
   }
 
   void
@@ -71,6 +70,14 @@ namespace edm {
     parameterSetID_ = pSetID;
   }
 
+  ProcessConfigurationID
+  ProcessConfiguration::setProcessConfigurationID() {
+    if(!transient_.pcid_.isValid()) {
+      transient_.pcid_ = id();
+    }
+    return transient_.pcid_;
+  }
+
   void
   ProcessConfiguration::reduce() {
     // Skip to the part of the release version just after
@@ -82,7 +89,7 @@ namespace edm {
     while(iter != iEnd && isdigit(*iter) == 0) ++iter;
     while(iter != iEnd && isdigit(*iter) != 0) ++iter;
     if (iter == iEnd) return;
-    setPCID(ProcessConfigurationID());
+    transient_.pcid_ = ProcessConfigurationID();
     releaseVersion_.erase(iter,iEnd);
   }
 
diff --git a/DataFormats/Provenance/src/ProcessHistory.cc b/DataFormats/Provenance/src/ProcessHistory.cc
index 4f5e8b1dd4032..5dfb49df87256 100644
--- a/DataFormats/Provenance/src/ProcessHistory.cc
+++ b/DataFormats/Provenance/src/ProcessHistory.cc
@@ -6,12 +6,11 @@
 
 #include "DataFormats/Provenance/interface/ProcessHistory.h"
 
-
 namespace edm {
   ProcessHistoryID
   ProcessHistory::id() const {
-    if(phid().isValid()) {
-      return phid();
+    if(transient_.phid_.isValid()) {
+      return transient_.phid_;
     }
     // This implementation is ripe for optimization.
     // We do not use operator<< because it does not write out everything.
@@ -24,9 +23,16 @@ namespace edm {
     }
     std::string stringrep = oss.str();
     cms::Digest md5alg(stringrep);
-    ProcessHistoryID tmp(md5alg.digest().toString());
-    phid().swap(tmp);
-    return phid();
+    ProcessHistoryID phID(md5alg.digest().toString());
+    return phID;
+  }
+
+  ProcessHistoryID
+  ProcessHistory::setProcessHistoryID() {
+    if(!transient_.phid_.isValid()) {
+      transient_.phid_ = id();
+    }
+    return transient_.phid_;
   }
 
   bool
diff --git a/DataFormats/Provenance/src/ProductProvenance.cc b/DataFormats/Provenance/src/ProductProvenance.cc
index e60a1d2f3cedd..660414cc112d0 100644
--- a/DataFormats/Provenance/src/ProductProvenance.cc
+++ b/DataFormats/Provenance/src/ProductProvenance.cc
@@ -54,7 +54,7 @@ namespace edm {
     parentageID_(),
     transient_() {
       parentagePtr() = boost::shared_ptr<Parentage>(new Parentage);
-      parentagePtr()->parents() = parents;
+      parentagePtr()->setParents(parents);
       parentageID_ = parentagePtr()->id();
       ParentageRegistry::instance()->insertMapped(*parentagePtr());
   }
diff --git a/DataFormats/Provenance/test/EntryDescription_t.cpp b/DataFormats/Provenance/test/EntryDescription_t.cpp
index a13e16bff3c0c..78b0dc60c598b 100644
--- a/DataFormats/Provenance/test/EntryDescription_t.cpp
+++ b/DataFormats/Provenance/test/EntryDescription_t.cpp
@@ -10,9 +10,9 @@ int main() {
   edm::Parentage ed2;
   assert(ed1 == ed2);
 
-  ed2.parents() = std::vector<edm::BranchID>(1);
+  ed2.setParents(std::vector<edm::BranchID>(1));
   edm::Parentage ed3;
-  ed3.parents() = std::vector<edm::BranchID>(2);
+  ed3.setParents(std::vector<edm::BranchID>(2));
 
   try {
     edm::ParentageID id1 = ed1.id();
@@ -27,7 +27,7 @@ int main() {
     assert(ed2 != ed3);
 
     edm::Parentage ed4;
-    ed4.parents() = std::vector<edm::BranchID>(1);
+    ed4.setParents(std::vector<edm::BranchID>(1));
     edm::ParentageID id4 = ed4.id();
     assert(ed4 == ed2);
     assert (id4 == id2);
diff --git a/FWCore/Framework/src/HistoryAppender.cc b/FWCore/Framework/src/HistoryAppender.cc
index 4717613ab74b3..ecb2436dbe3cd 100644
--- a/FWCore/Framework/src/HistoryAppender.cc
+++ b/FWCore/Framework/src/HistoryAppender.cc
@@ -39,7 +39,7 @@ namespace edm {
     checkProcessHistory(newProcessHistory, pc);
     newProcessHistory.push_back(pc);
     registry->insertMapped(newProcessHistory);
-    ProcessHistoryID newProcessHistoryID = newProcessHistory.id();
+    ProcessHistoryID newProcessHistoryID = newProcessHistory.setProcessHistoryID();
     CachedHistory newValue(inputProcessHistory,
                            registry->getMapped(newProcessHistoryID),
                            newProcessHistoryID);
diff --git a/FWCore/Framework/src/Schedule.cc b/FWCore/Framework/src/Schedule.cc
index 77954651f4ed4..b2bdb87653895 100644
--- a/FWCore/Framework/src/Schedule.cc
+++ b/FWCore/Framework/src/Schedule.cc
@@ -395,6 +395,7 @@ namespace edm {
     proc_pset.registerIt();
     pset::Registry::instance()->extra().setID(proc_pset.id());
     processConfiguration->setParameterSetID(proc_pset.id());
+    processConfiguration->setProcessConfigurationID();
 
     initializeEarlyDelete(opts,preg,subProcPSet);
     
diff --git a/FWCore/Integration/test/ProcessHistory_t.cpp b/FWCore/Integration/test/ProcessHistory_t.cpp
index a7b30c96a05fb..05ec2545bc127 100644
--- a/FWCore/Integration/test/ProcessHistory_t.cpp
+++ b/FWCore/Integration/test/ProcessHistory_t.cpp
@@ -51,9 +51,9 @@ int main() try {
   pnl3.push_back(iHLT);
   pnl3.push_back(iRECO);
 
-  edm::ProcessHistoryID id1 = pnl1.id();
-  edm::ProcessHistoryID id2 = pnl2.id();
-  edm::ProcessHistoryID id3 = pnl3.id();
+  edm::ProcessHistoryID id1 = pnl1.setProcessHistoryID();
+  edm::ProcessHistoryID id2 = pnl2.setProcessHistoryID();
+  edm::ProcessHistoryID id3 = pnl3.setProcessHistoryID();
 
   assert(id1 != id2);
   assert(id2 != id3);
@@ -61,7 +61,7 @@ int main() try {
 
   edm::ProcessHistory pnl4;
   pnl4.push_back(iHLT);
-  edm::ProcessHistoryID id4 = pnl4.id();
+  edm::ProcessHistoryID id4 = pnl4.setProcessHistoryID();
   assert(pnl4 == pnl2);
   assert (id4 == id2);
 
@@ -80,14 +80,14 @@ int main() try {
   edm::ProcessConfiguration pc7(std::string("HLT"), psetID, std::string("xb500yz872djk999patch10"), edm::getPassID());
   edm::ProcessConfiguration pc8(std::string("HLT"), psetID, std::string("CMSSW_4_4_0_pre5"), edm::getPassID());
 
-  pc1.id();
-  pc2.id();
-  pc3.id();
-  pc4.id();
-  pc5.id();
-  pc6.id();
-  pc7.id();
-  pc8.id();
+  pc1.setProcessConfigurationID();
+  pc2.setProcessConfigurationID();
+  pc3.setProcessConfigurationID();
+  pc4.setProcessConfigurationID();
+  pc5.setProcessConfigurationID();
+  pc6.setProcessConfigurationID();
+  pc7.setProcessConfigurationID();
+  pc8.setProcessConfigurationID();
 
   pc1.reduce();
   pc2.reduce();
@@ -134,7 +134,7 @@ int main() try {
   phTestExpected.push_back(iRECOreduced);
 
   edm::ProcessHistory phTest = pnl3;
-  phTest.id();
+  phTest.setProcessHistoryID();
   phTest.reduce();
   assert(phTest == phTestExpected);
   assert(phTest.id() == phTestExpected.id());
@@ -189,14 +189,14 @@ int main() try {
     ph3.push_back(pc3);
     ph4.push_back(pc4);
 
-    edm::ProcessHistoryID phid1 = ph1.id();
-    edm::ProcessHistoryID phid1a = ph1a.id();
-    edm::ProcessHistoryID phid1b = ph1b.id();
-    edm::ProcessHistoryID phid2 = ph2.id();
-    edm::ProcessHistoryID phid2a = ph2a.id();
-    edm::ProcessHistoryID phid2b = ph2b.id();
-    edm::ProcessHistoryID phid3 = ph3.id();
-    edm::ProcessHistoryID phid4 = ph4.id();
+    edm::ProcessHistoryID phid1 = ph1.setProcessHistoryID();
+    edm::ProcessHistoryID phid1a = ph1a.setProcessHistoryID();
+    edm::ProcessHistoryID phid1b = ph1b.setProcessHistoryID();
+    edm::ProcessHistoryID phid2 = ph2.setProcessHistoryID();
+    edm::ProcessHistoryID phid2a = ph2a.setProcessHistoryID();
+    edm::ProcessHistoryID phid2b = ph2b.setProcessHistoryID();
+    edm::ProcessHistoryID phid3 = ph3.setProcessHistoryID();
+    edm::ProcessHistoryID phid4 = ph4.setProcessHistoryID();
 
     edm::ProcessHistoryRegistry::instance()->insertMapped(ph1);
     edm::ProcessHistoryRegistry::instance()->insertMapped(ph1a);
diff --git a/FWCore/ParameterSet/src/FillProductRegistryTransients.cc b/FWCore/ParameterSet/src/FillProductRegistryTransients.cc
index 4363dac7503ea..94a0cff95619a 100644
--- a/FWCore/ParameterSet/src/FillProductRegistryTransients.cc
+++ b/FWCore/ParameterSet/src/FillProductRegistryTransients.cc
@@ -27,7 +27,7 @@ namespace edm {
     std::string const& processName = pc.processName();
     ParameterSetID const& processParameterSetID = pc.parameterSetID();
     ParameterSet const* processParameterSet = pset::Registry::instance()->getMapped(processParameterSetID);
-    if(0 == processParameterSet || processParameterSet->empty()) {
+    if(nullptr == processParameterSet || processParameterSet->empty()) {
       return;
     }
     for(ProductRegistry::ProductList::iterator it = preg.productListUpdator().begin(),
diff --git a/FWCore/Sources/src/DaqProvenanceHelper.cc b/FWCore/Sources/src/DaqProvenanceHelper.cc
index 3a51f07fdf4aa..f12c3f9720fb8 100644
--- a/FWCore/Sources/src/DaqProvenanceHelper.cc
+++ b/FWCore/Sources/src/DaqProvenanceHelper.cc
@@ -89,7 +89,7 @@ namespace edm {
     ProcessConfigurationRegistry::instance()->insertMapped(pc);
 
     // Save the process history ID for use every event.
-    return ph.id();
+    return ph.setProcessHistoryID();
   }
 
   bool
diff --git a/IOPool/Input/src/RootFile.cc b/IOPool/Input/src/RootFile.cc
index 2a6055d6bb74b..f633b9f4841fa 100644
--- a/IOPool/Input/src/RootFile.cc
+++ b/IOPool/Input/src/RootFile.cc
@@ -502,10 +502,10 @@ namespace edm {
       }
       oldregistry.insertMapped(entryDescriptionBuffer);
       Parentage parents;
-      parents.parents() = entryDescriptionBuffer.parents();
+      parents.setParents(entryDescriptionBuffer.parents());
       if(daqProvenanceHelper_) {
         ParentageID const oldID = parents.id();
-        daqProvenanceHelper_->fixMetaData(parents.parents());
+        daqProvenanceHelper_->fixMetaData(parents.parentsForUpdate());
         ParentageID newID = parents.id();
         if(newID != oldID) {
           daqProvenanceHelper_->parentageIDMap_.insert(std::make_pair(oldID, newID));
@@ -543,7 +543,7 @@ namespace edm {
       roottree::getEntry(parentageTree.get(), i);
       if(daqProvenanceHelper_) {
         ParentageID const oldID = parents.id();
-        daqProvenanceHelper_->fixMetaData(parents.parents());
+        daqProvenanceHelper_->fixMetaData(parents.parentsForUpdate());
         ParentageID newID = parents.id();
         if(newID != oldID) {
           daqProvenanceHelper_->parentageIDMap_.insert(std::make_pair(oldID, newID));
diff --git a/IOPool/SecondaryInput/test/SecondaryProducer.cc b/IOPool/SecondaryInput/test/SecondaryProducer.cc
index a9269d9b47906..9cc19e79bcce9 100644
--- a/IOPool/SecondaryInput/test/SecondaryProducer.cc
+++ b/IOPool/SecondaryInput/test/SecondaryProducer.cc
@@ -54,6 +54,7 @@ namespace edm {
     ParameterSet emptyPSet;
     emptyPSet.registerIt();
     processConfiguration_->setParameterSetID(emptyPSet.id());
+    processConfiguration_->setProcessConfigurationID();
  
     productRegistry_->setFrozen();