diff --git a/PROMS/Volian.Controls.Library/DisplayApplicability.cs b/PROMS/Volian.Controls.Library/DisplayApplicability.cs
index 67f01532..56e270b2 100644
--- a/PROMS/Volian.Controls.Library/DisplayApplicability.cs
+++ b/PROMS/Volian.Controls.Library/DisplayApplicability.cs
@@ -212,7 +212,9 @@ namespace Volian.Controls.Library
 			//  }
 			//}
 			List<InvalidTransition> invalidTrans = WillTransitionsBeValidCommand.Execute(MyItemInfo.ItemID, MyApplicability);
-			if (invalidTrans.Count == 0)
+			// B2021-149: for Procedure level PC/PC, continue processing if all 'invalid' transitions are internal (query used
+			//	return internal and external for the procedure level)
+			if ((!MyItemInfo.IsProcedure && invalidTrans.Count == 0) || IsProcWithNoExternalTrans(MyItemInfo, invalidTrans))
 			{
 				// C2021 - 027: Procedure level PC/PC
 				if (MyItemInfo.IsProcedure && MyItemInfo.ActiveFormat.PlantFormat.FormatData.ProcData.ProcAppl)
@@ -236,8 +238,11 @@ namespace Volian.Controls.Library
 				StringBuilder sb = new StringBuilder();
 				sb.AppendLine("Changing the applicability for this step will invalidate a transition in the following steps...");
 				sb.AppendLine();
+				// B2021-149: if step, put out line for every invalidTrans, if procedure only put out those that are external
+				//	determine this by looking strings for source and target (to), if procedure level and internal the target starts
+				//	with the src, i.e. procedure.
 				foreach (InvalidTransition inv in invalidTrans)
-					sb.AppendLine(string.Format("From {0} to {1}", inv.SrcStep, inv.TgtStep));
+					if (!MyItemInfo.IsProcedure || !inv.TgtStep.StartsWith(inv.SrcStep))sb.AppendLine(string.Format("From {0} to {1}",inv.TgtStep, inv.SrcStep));
 	//			MessageBox.Show(sb.ToString());
 				// B2013-185  use FlexibleMessageBox to display a long list with a scroll bar
 				FlexibleMessageBox.Show(sb.ToString(), "Transitions Affected By Applicability Change");
@@ -261,6 +266,18 @@ namespace Volian.Controls.Library
 			//  s.Save();
 			//}
 		}
+		// B2021-149: for procedure, only consider external transitions as invalid
+		private bool IsProcWithNoExternalTrans(ItemInfo ii, List<InvalidTransition> invalidTrans)
+		{
+			if (invalidTrans.Count == 0) return true;
+			foreach (InvalidTransition iT in invalidTrans)
+			{
+				// if target (to location) does not start with source location (procedure) then this is external
+				//	i.e. from a different procedure
+				if (!iT.TgtStep.StartsWith(iT.SrcStep)) return false;
+			}
+			return true;
+		}
 		private bool AllNumbered(CheckState checkState)
 		{
 			foreach (CheckBox cb in MyCheckBoxes.Values)