Assuming it isn't a 803H bug thwarting the 'constrained material' functionality (we are still piloting on 803F - leaving the sufferance of bugs to other guinea pigs!), I don't think Locking your furnace jobs is the answer (but I would definitely try it in a copied full db of the live system).
Perhaps Locking them and also setting each Furnace level part so MRP isn't try to plan them would work as, it sounds like either the Global Scheduler, MRP (if you are running it with the 'run Finite scheduling' box checked) and/or the single order scheduler (which you want to be sure you run in Finite mode) is assuming it can produce anything it needs from your Furnace operation in 12 hours (starting immediately - even if something else is scheduled).
The single order scheduler doesn't seem to give a hoot about creating (in your case - a part "B" schedule) - even when it overloads a resource needed to produce a required part "C" (and even when run in finite mode).
Is it impractical to use Timephase Inquiry on the required C level part and then simply to specify a valid start date for part B? It will only 'stick' until the Global is run, but at least you could determine a valid part A fulfillment plan, specify that 'best possible' date at part A as the Req'd by date - and then backward schedule part levels A and B.
What also might work is to master scheduled all of your furnace jobs. The problem with master scheduling at that "C" BOM level is that it will never experience independent demand (so your master scheduled demand will never be 'consumed'), However, if you set your Furnace parts' Min order qty's to match the qty you typically plan to produce in whatever frequency you would define for the each part's master schedule period - and then just master schedule 1 pc per part each period, MRP will create unfirmed orders matching your plan in the Min Order Qty of each part in whatever M/S period frequency you specified. The M/S demand of 1 pc - even though it won't be 'consumed' by actual dependant demand at BOM B levels, shouldn't skew your planning messages much.
Depending upon the number of "C" level parts, you could however be setting yourself up for soem heavy planner maintenance time required constantly tweak your master schedules.
One last avenue to explore: Use CTP at the part A level and 'trick it' by telling it you want part A today. That might give you an accurate 'earliest possible' date.
I share your frustration... I've used schedulers on $10,000 systems that work better than this...
Please let me know how you make out.
Rob Brown
Versa Products
jwarshawer <
john@...> wrote: Robert,
I think that what you are describing as a horrible shortcoming of
Vantage is exactly what I am looking for.
At my client, they want to forward schedule to tell the customer the
earliest date we can deliver the order. Therefore, we want to
schedule the jobs as soon as the contrained material is available.
All the discussions about this have been related to Purchased
material. For us, our purchased raw material is plentiful, cheap,
and has a very short leadtime. For use the bottleneck is our furnace
runs, which make all the product for the upstream jobs (all make-to-
stock). It is from these furnaces that we want to Forward Schedule.
We have been unable to make this work.
From your experience, if I schedule and lock the furnace job, should
the Forward Scheduler plan upstream jobs based on the completion date
of the furnace run?
Thanks so much for your help.
--- In
vantage@yahoogroups.com, Robert Brown <robertb_versa@...>
wrote:
>
> Vantage 8.03 does consider material availability when scheduling a
Job - but you still may not get the behavior you desire and described
in your example.
>
> If the lead time you have indicated 'Material X' has is less days
than the number of days between 'today' and your PO scheduled due
date of 8/20 for 'Material X', the scheduler will assume you can can
start the Job before 8/20. It will start the Job on whatever
date 'today' plus your indicated Material X lead time is.
>
> Depending upon how you have set other planning data for Material
X (and time phased demand conditions), MRP will then either suggest a
planned order to bring in Material X just in time to start your Job
on the earlier than 8/20 date OR it will suggest moving the scheduled
receipt date of the PO IN.
>
> Your scenario will only work if Material X's indicated lead time
is greater than the time between 'today' and 8/20.
>
> Unfortunately, because of Vantage 8's woefully inadequate support
of Forward scheduling, you'll have to look to the other available
means to force your Jobs to start on a specific firm date.
>
> For whatever reason, Vantage scheduling module designers
understood that a backward scheduled job should be backward scheduled
from the entered/desired Due Date - but clearly didn't/still-don't
understand the forward scheduled jobs should not be started before a
user-defined/entered Start date. In Vantage, if a Job has been
assigned a Forward scheduling Scheduling Priority, is Engineered and
is not "Locked" (marked as not reschedulable), Vantage forward
scheduling will schedule the job to start as soon as it thinks
material will be available - even if the Job only requires
hours/minutes to physically complete and you don't want/need it
completed for weeks/months/years in the future.
>
> Perhaps "woefully inadequate" wasn't strong enough as this is
late 1960's MRPII capability it doesn't support.
>
> Not knowing the complexity of your scheduling model (or your
available human resources dedicated to managing them), I can not
offer any specific solutions but potential options are:
>
> Backward schedule - If you are NOT in an environment where
completing the Job as soon as possible (once necessary raw materials
are available) allows you to ship invoicable product sooner, Backward
scheduling may be a solution for you. Just be aware that use of
different Scheduling Priority code 'multipliers' to prioritize
certain Jobs over others is ineffective under Backward scheduling as
a higher priority order will be attempted to be started just in time
to complete by the Due (and lower priority assigned orders will end
up starting and finishing earlier if finite resource capacity
exists). - Completely backwards behavior to handle typical real world
needs.
> Forward schedule your newly created Jobs, immediately use the
(laborious to use) Job Scheduling Board application to forceably
Start the new job on the date you wish to respect - and then Lock the
job so the Global scheduler won't move it. However, unless the
complexity of your methods, the number of resources being scheduled,
and the number of Jobs in the system are VERY low, this is a no win
situation as, by Locking jobs, you prevent the global scheduler from
utilizing all available capacity as time marches on. You would
essentially be setting yourself up for manually scheduling every
operation in your shop to keep schedules 'tight', fully utilize
available resources, and have reasonable accurate Job completion
dates to base sales order promises (and other Job production if you
have complex multi level BOM structures that must be produced and
managed).
> Master Schedule at the independent demand level if you have
product BOM structures no more than 3 levels deep (and have
relatively few 'top level' items that experience indepenent sales
demand - AND you are confident you can forecast them accurately).
> 'Go Lean' and convert as much of your purchased raw material
suppliers to Contract POs as possible (or vendor Kan-Ban processes) -
buffering the heck out of the purchased materials with
prudently/safely high specified Min on-hands (and/or Safety Stock as
they both result in identical MRP behavior in Vantage) - and then
ignore MRP suggested Jobs until the last possible moment (so you
don't start forward scheduled jobs needlessly too soon, watch
helplessly as your resource schedules falsely become overloaded - and
your inventory balloons). Concurrently, convert as many of your
fabrication processes as possible so they are suitable to set the
produced SKUs as Kan-Ban items. This is absolutely the way to go if
you really can put the physical systems in place so you can 'go deep'
and do it concurrently at every level of a single product's BOM
structure (and then moving on to the next product, and the next until
all are done). It is a huge paradigm shift however (mentally - at
> all levels of a manufacturing organization). That is important to
be aware of as, if you only 'nibble at it' and 'go wide' (perhaps
physically implementing Lean at a common 'cellular' similar process
SKU level that sits in the middle of many product structures), it
will be difficult to physically manage and sustain - and it will be
difficult for your planners as they will be mentally having to shift
their thinking between the polar opposite paradigms of Lean-pull to
demand and MRP-push to plan.
> Somewhere amongst those basic options, you can likely find
a 'least worst' hybrid planning process that will be sufficient to
manage your schedules and achieve your business goals in a way that
is suitable to your markets.
>
> Good luck! (and let us know if you discover a better way to
overcome Vantage's gaping scheduling weaknesses!)
>
> Rob Brown
> Versa Products
>
>
> bbelzer42 <bbelzer@...> wrote:
> Can anyone confirm or deny that Vantage 8 will allow my
schedule to
> know when a material will be arriving, based on due date (not lead
> time), and schedule the job to start accordingly?
>
> Example:
> PO 1234 for Material X is due on August 20th. When I forward
schedule
> I want Vantage to look at the PO and start the job on the 20th or
21st
> of August.
>
> Will Vantage 8 do this? Maybe 8.3?
>
> Thanks!
> Ben
>
>
>
>
>
>
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