Ben,
Indeed, in 6.1 finite scheduling is only used in Global Finite
Scheduling (GFS). It works pretty well if you get all the data setup
properly including workcenter hours, calendars etc. In 6.1, GFS only
considers the work centers - no other finite constrains are available.
We "model" other constrains such as labor by reducing the available
hours for the machine work centers, an inperfect approach but it works
approximately.
In 6.1 - Materials are not constraining unless they are non-stock parts
and then the GFS only considers the lead time value on the JobMatl
record and does not look at any associated source such as a PO or Job.
Similarly for Sub-Contract ops it only considers the "Days Out"
parameter and does not look at an associated PO. Also be aware that
even completed non-stock materials with a non-zero lead time may cause a
delay if they are associated with a job op (I think I remember that
correctly, it has been a while since I figure that problem out)
I have fixed all of these problems using ODBC and Access to run my own
time phase like analysis and update the "Lead Time" and "Days Out"
values appropriately before the GFS runs. In addition, I store the
source of supply for all materials in a user supplied field. To handle
job-to-job (View as Material sub-assemblies if you will) supplies I run
the global multiple times and introduce psuedo-material record which
delays the fed job until the feeder job is finished. This requires
multiple runs of the GFS to work (and then only approximately). Once
the GFS has finished the pseudo-materials are deleted. All this is
automated through Access and a scripting tool which runs the GFS in
vantage. (I also use the pseudo-materials to give me a "Delay Until"
capability which is specificed via a VB form field and to force a supply
delay even on "stock" materials which are currently on order).
I use forward scheduling on all jobs whose start date is with 70 days
and backward only on those jobs beyond that horizon. Vantage 6.1
backward scheduling does not always "bounce" properly if jobs backup
into the past. This switch from backward to forward is also handled by
the Access program.
You must also be very careful of locked jobs. Vantage GFS will not
modify locked jobs - even if they are locked in the past. Essentially
locked jobs have the highest priority in the GFS run since they are
placed on the schedule first and everything else works around them. To
prevent this I clear the lock flag before GFS if the first incomplete op
is scheduled in the past and raise the priority (again with Access).
I realize that using ODBC/Access to write to the Vantage DB is not
considered acceptable, but there is really no other practical way to do
it in 6.1 and I don't believe that I violate any of the business logic
in Vantage which is enforced by the triggers on the associated records -
except of course that change logging is not recorded on those fields,
something I really would not want anyway.
I hope this helps. Please contact me off-line if you want anymore
information.
Mercer Sisson
Hello,
When I schedule a job through Job Entry it doesn't finitely schedule the
job. Is that normal?
If I forward schedule a job (the work centers are all checked as
finite) it starts the first operation immediately even if there is a
current operation for that machine. It does not wait for gaps in the
schedule.
I swear it used to look for gaps.
Any insight would be fantastic...
Thanks!!!
-Ben
------------------------------------
Useful links for the Yahoo!Groups Vantage Board are: ( Note: You must
have already linked your email address to a yahoo id to enable access. )
(1) To access the Files Section of our Yahoo!Group for Report Builder
and Crystal Reports and other 'goodies', please goto:
http://groups.yahoo.com/group/vantage/files/.
(2) To search through old msg's goto:
http://groups.yahoo.com/group/vantage/messages
(3) To view links to Vendors that provide Vantage services goto:
http://groups.yahoo.com/group/vantage/linksYahoo! Groups Links
Indeed, in 6.1 finite scheduling is only used in Global Finite
Scheduling (GFS). It works pretty well if you get all the data setup
properly including workcenter hours, calendars etc. In 6.1, GFS only
considers the work centers - no other finite constrains are available.
We "model" other constrains such as labor by reducing the available
hours for the machine work centers, an inperfect approach but it works
approximately.
In 6.1 - Materials are not constraining unless they are non-stock parts
and then the GFS only considers the lead time value on the JobMatl
record and does not look at any associated source such as a PO or Job.
Similarly for Sub-Contract ops it only considers the "Days Out"
parameter and does not look at an associated PO. Also be aware that
even completed non-stock materials with a non-zero lead time may cause a
delay if they are associated with a job op (I think I remember that
correctly, it has been a while since I figure that problem out)
I have fixed all of these problems using ODBC and Access to run my own
time phase like analysis and update the "Lead Time" and "Days Out"
values appropriately before the GFS runs. In addition, I store the
source of supply for all materials in a user supplied field. To handle
job-to-job (View as Material sub-assemblies if you will) supplies I run
the global multiple times and introduce psuedo-material record which
delays the fed job until the feeder job is finished. This requires
multiple runs of the GFS to work (and then only approximately). Once
the GFS has finished the pseudo-materials are deleted. All this is
automated through Access and a scripting tool which runs the GFS in
vantage. (I also use the pseudo-materials to give me a "Delay Until"
capability which is specificed via a VB form field and to force a supply
delay even on "stock" materials which are currently on order).
I use forward scheduling on all jobs whose start date is with 70 days
and backward only on those jobs beyond that horizon. Vantage 6.1
backward scheduling does not always "bounce" properly if jobs backup
into the past. This switch from backward to forward is also handled by
the Access program.
You must also be very careful of locked jobs. Vantage GFS will not
modify locked jobs - even if they are locked in the past. Essentially
locked jobs have the highest priority in the GFS run since they are
placed on the schedule first and everything else works around them. To
prevent this I clear the lock flag before GFS if the first incomplete op
is scheduled in the past and raise the priority (again with Access).
I realize that using ODBC/Access to write to the Vantage DB is not
considered acceptable, but there is really no other practical way to do
it in 6.1 and I don't believe that I violate any of the business logic
in Vantage which is enforced by the triggers on the associated records -
except of course that change logging is not recorded on those fields,
something I really would not want anyway.
I hope this helps. Please contact me off-line if you want anymore
information.
Mercer Sisson
Hello,
When I schedule a job through Job Entry it doesn't finitely schedule the
job. Is that normal?
If I forward schedule a job (the work centers are all checked as
finite) it starts the first operation immediately even if there is a
current operation for that machine. It does not wait for gaps in the
schedule.
I swear it used to look for gaps.
Any insight would be fantastic...
Thanks!!!
-Ben
------------------------------------
Useful links for the Yahoo!Groups Vantage Board are: ( Note: You must
have already linked your email address to a yahoo id to enable access. )
(1) To access the Files Section of our Yahoo!Group for Report Builder
and Crystal Reports and other 'goodies', please goto:
http://groups.yahoo.com/group/vantage/files/.
(2) To search through old msg's goto:
http://groups.yahoo.com/group/vantage/messages
(3) To view links to Vendors that provide Vantage services goto:
http://groups.yahoo.com/group/vantage/linksYahoo! Groups Links