diff --git a/src/main/java/com/inteligr8/maven/aps/modeling/translator/ApsProcessJsonTranslator.java b/src/main/java/com/inteligr8/maven/aps/modeling/translator/ApsProcessJsonTranslator.java
index 881db9a..6051d80 100644
--- a/src/main/java/com/inteligr8/maven/aps/modeling/translator/ApsProcessJsonTranslator.java
+++ b/src/main/java/com/inteligr8/maven/aps/modeling/translator/ApsProcessJsonTranslator.java
@@ -241,24 +241,30 @@ public class ApsProcessJsonTranslator extends ApsOrganizationHandler implements
 		String idField = prefix == null ? "id" : prefix + "Id";
 		
 		ObjectNode jsonRef = (ObjectNode)_jsonRef;
-		String modelName = jsonRef.get(nameField).asText();
-		this.logger.trace("Found model '{}' in the APS Process descriptor", modelName);
-		
-		if (apsIndex.containsValue(modelName)) {
-			long modelId = jsonRef.get(idField).asLong();
-			long apsModelId = apsIndex.getFirstKey(modelName);
-			if (apsModelId != modelId) {
-				this.logger.debug("The model '{}' exists in APS with ID {}; leaving unchanged", modelName, apsModelId);
-				jsonRef.put(idField, apsModelId);
-				return true;
-			} else {
-				this.logger.trace("The model '{}' ID does not change; leaving unchanged", modelName);
-			}
-		} else {
-			this.logger.debug("The model '{}' does not exists in APS; leaving unchanged", modelName);
+		JsonNode jsonName = jsonRef.get(nameField);
+		if (jsonName == null) {
+            this.logger.trace("The expression does not have an APS model name field ({})", nameField);
+            return false;
 		}
 		
-		return false;
+		String modelName = jsonName.asText();
+		this.logger.trace("Found model '{}' in the APS Process descriptor", modelName);
+		if (!apsIndex.containsValue(modelName)) {
+            this.logger.debug("The model '{}' does not exists in APS; leaving unchanged", modelName);
+            return false;
+		}
+		
+		JsonNode jsonId = jsonRef.get(idField);
+		long modelId = jsonId == null ? -1L : jsonId.asLong();
+		long apsModelId = apsIndex.getFirstKey(modelName);
+		if (apsModelId != modelId) {
+			this.logger.debug("The model '{}' exists in APS with ID {}", modelName, apsModelId);
+			jsonRef.put(idField, apsModelId);
+			return true;
+		} else {
+			this.logger.trace("The model '{}' ID does not change; leaving unchanged", modelName);
+	        return false;
+		}
 	}