diff --git a/TODO b/TODO
index 936415a..a91f49d 100644
--- a/TODO
+++ b/TODO
@@ -1,8 +1,4 @@
 ## GENERAL
-    * optimise run_ai_on (and for that matter getfiledetails, etc.)...
-        - e.g. with last scan*, STORE: new files?
-        - if last scan no new files, dont getfiledetails, don't re-run ai job
-
     * per file you could select an unknown face and add it as a ref img to an existing person, or make a new person and attach?
         * [DONE] order/ find face with largest size and at least show that as unmatched
             - could also try to check it vs. other faces, if it matches more than say 10? we offer it up as a required ref img, then cut that face (with margin) out and use it is a new ref image / person
diff --git a/pa_job_manager.py b/pa_job_manager.py
index 517e19b..a4fe134 100644
--- a/pa_job_manager.py
+++ b/pa_job_manager.py
@@ -13,11 +13,6 @@
 
 # pylint: disable=no-member
 
-
-# global debug setting
-if os.environ['FLASK_ENV'] != "production":
-    DEBUG=True
-
 ### SQLALCHEMY IMPORTS ###
 from sqlalchemy.ext.declarative import declarative_base
 from sqlalchemy import Column, Integer, String, Sequence, Float, ForeignKey, DateTime, LargeBinary, Boolean, func
@@ -52,6 +47,10 @@ import sys
 import json
 
 
+# global debug setting
+if 'FLASK_ENV' not in os.environ or os.environ['FLASK_ENV'] != "production":
+    DEBUG=True
+
 # this is required to handle the duplicate processing code
 sys.setrecursionlimit(50000)
 
@@ -685,16 +684,6 @@ def RunJob(job):
     HandleJobs(False)
     return
 
-##############################################################################
-# CancelJob(): cancel this job, and if any other job is waiting on this job,
-# then cancel it too (this is done recursively)
-##############################################################################
-def CancelJob(job,id):
-    for j in session.query(Job).filter(Job.wait_for==id).all():
-        FinishJob(j, f"Job (#{j.id}) has been withdrawn as the job being waited for #{job.id} failed", "Withdrawn" )
-        CancelJob(j, j.id)
-    return
-
 ##############################################################################
 # FinishJob(): finish this job off (if no overrides), its just marked completed
 ##############################################################################
@@ -704,7 +693,7 @@ def FinishJob(job, last_log, state="Completed", pa_job_state="Completed"):
     job.last_update=datetime.now(pytz.utc)
     AddLogForJob(job, last_log)
     if job.state=="Failed":
-        CancelJob(job,job.id)
+        WithdrawDependantJobs( job, job.id, "failed" ):
     session.commit()
     if DEBUG:
         print( f"DEBUG: {last_log}" )
@@ -1254,6 +1243,17 @@ def AddJexToDependantJobs(job,name,value):
         AddJexToDependantJobs(j, name, value)
     return
 
+####################################################################################################################################
+# WithdrawDependantJobs(): cancel/withdraw this dependant job, and if any other job is waiting on it then 
+# cancel it too (this is done recursively)
+####################################################################################################################################
+def WithdrawDependantJobs( job, id, reason ):
+    for j in session.query(Job).filter(Job.wait_for==id).all():
+        FinishJob(j, f"Job (#{j.id}) has been withdrawn -- #{job.id} {reason}", "Withdrawn" )
+        WithdrawDependantJobs(j, j.id, reason)
+    return
+    
+
 ####################################################################################################################################
 # JobImportDir(): job that scan import dir and processes entries in there - key function that uses os.walk() to traverse the 
 # file system and calls AddFile()/AddDir() as necessary
@@ -1268,6 +1268,7 @@ def JobImportDir(job):
     if DEBUG:
         print( f"DEBUG: Checking Directory: {path}" )
     if not os.path.exists( path ):
+        WithdrawDependantJobs( job, job.id, "scan job found no new files to process" )
         FinishJob( job, f"Finished Importing: {path} -- Path does not exist", "Failed" )
         return
     symlink=SymlinkName(ptype.name, path, path)
@@ -1302,6 +1303,9 @@ def JobImportDir(job):
     AddLogForJob(job, f"Found {overall_file_cnt} file(s) to process")
     session.commit()
 
+    # we will store this into the job extras as the final result of whether this job found any new files, 
+    # if it did not, then the dependant jobs dont need to really run - use to optimise them
+    found_new_files=0
     # root == path of dir, files are in dir... subdirs are in dir 
     for root, subdirs, files in ftree:
         # already create root above to work out num_files for whole os.walk
@@ -1331,6 +1335,7 @@ def JobImportDir(job):
 
                 year, month, day, woy = GetDateFromFile(fname, stat)
                 e=AddFile( job, basename, type_str, fsize, dir, year, month, day, woy )
+                found_new_files += 1
             else:
                 if DEBUG:
                     print( f"DEBUG: { basename} - {stat.st_ctime} is OLDER than {dir.last_import_date}" )
@@ -1344,7 +1349,9 @@ def JobImportDir(job):
 
     rm_cnt=HandleAnyFSDeletions(job)
 
-    FinishJob(job, f"Finished Importing: {path} - Processed {overall_file_cnt} files, Removed {rm_cnt} file(s)")
+    if found_new_files == 0:
+        WithdrawDependantJobs( job, job.id, "scan job found no new files to process" )
+    FinishJob(job, f"Finished Importing: {path} - Processed {overall_file_cnt} files, Found {found_new_files} new files, Removed {rm_cnt} file(s)")
     return
 
 ####################################################################################################################################