Just looking to see if someone can shed some light on what may be wrong here, this is the time phase at the manufacturing for one of our parts, and once it’s completed manufacturing it then gets transferred to another site. However, what we’re seeing here is that the balance column is going negative and we’re unsure as to why.
There is no min/max/safety quantity at this site, but there is at the site it gets transferred too, demand is driven from that site as well.
Timephase is just math. It takes the quantity on hand as the starting point and then everything from there either takes away or adds to the quantity depending on the transaction type.
A few other thoughts:
You have a sort on one of the columns and that messes up the sense of this. The rows appear out of order when looking at the balance.
Also, this is a good start for understanding this system. But to avoid actually running out, you want to set your parts with a “receive time” of at least 1.
Hi Jason,
Just curious on the receive time of 1. Have you seen issues when it’s set to 0?
Thanks
So, you get a PO suggestion or unfirm job or transfer suggestion if and only if a part goes negative (or maybe also when it hits exactly zero).
Rough example:
This means that even if you never have supply issues or problems internally, you are still going to run out on the day that the PO arrives. So if the truck comes in the afternoon, there are people waiting for parts in your plant because you are cutting it so close.
But with a receive time of 1, the suggestion will be for the PO to arrive the day before, on the 18th. And then you will survive.
Thanks Jason. I will look into DMT’ing a value as I don’t think we’re using.
Most of our parts have a receive time in place already, the only part where we’re confused is that shouldn’t MRP not be letting the stock on hand go negative? The site in the screenshot above doesn’t have any min/max/safety stock, but the site the stock gets transfer into does (where we sell form).
The trend i’m seeing is that as stock gets consumed at the site we sell from, MRP suggests to transfer more from our manufacturing site to satisfy the min+safety stock quantity. But this causes time phase to show negative quantites
I would think it should suggest to increase the quantity on our jobs so that we wouldn’t go negative, but it isn’t the case.
So these negative balances are in the past (date of June 16 2022). Unless you Allow Historical Dates on MRP, it’s only going to create suggestions from today forward… if you look further down the grid and get to current date (+ manufacturing lead time) you should see suggestions that will bring your stock level up to your min+safety level.
Unless I’m missing something (which is entirely possible)…
Are you jobs set to lock quantity:
Also, on the planning tab for the part you can set values to ensure you’re jobs are a certain size and MRP will not suggest increasing:
A setting I am not using but have read about is that are “planning fences” this tells MRP not to suggest changes to job quantities within a certain date range
