Thank you for trying OrderSys and LabStoRe.
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I never had a feedback on integrating either of the two software in CMS's like Joomla or Drupal. I am curious about how you did your integration. Was it 'painful', for example? Would better developer-oriented documentation have helped with a speedier integration process? Did you have to modify the OrderSys/LabStoRe code outside config.php? Do you still have to have separate login processes (log into Joomla first and then OrderSys again, for instance)?
I am developing version 2 for both applications, and easy integration is one of the objectives (by allowing custom cookie names and applicable domains, user authentication tables, PHP session storage paths, etc.).
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The new versions will also optionally allow OrderSys-LabStoRe integration through a single login system, as well as achieve what you want currently. For OrderSys there will also be a way to place item requests that a 'manager' will put in to the actual order. There will be other features like the ability to email and fax the orders.
Do let me know of specific features that you would like to see.
Both software were written primarily for the one lab I was in, and the feature-set in the applications was dictated by the practices and expectations of that lab's members. I am no longer in that lab, nor do I use the software, but I'd like to keep developing them. Knowing that others might find such software useful is a motivational boost :)
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For your current setup, I understand that you want to avoid unnecessary ordering by making users check for the possible availability of items in the lab inventory (as maintained in LabStoRe).
OrderSys essentially contains a catalog of items. To place orders, users pick items by browsing/searching the catalog (adding new items when they don't find any). On the tables that list the items, it is easy to have links next to items such that clicking them will search LabStoRe and tell one if an item (or a similar one) exists.
Alternately, though using a bit more complex code, the OrderSys item tables can have information on the inventory status of the items. This saves users needing to click (as in the first strategy), and keeps them on the OrderSys pages.
Either way, the next issue is how should the application behave if an item exists but a user still wants to place an order. One option is to disable the check-box used to select the item to order.
One feature missing in LabStoRe is about the current stock status of items indicated using terms such as 'finished', 'close to finished', 'adequate', and so on. If such information was available, then the item quantity level could be used to decide when to disable the ordering of the item. That way, a user could order an item if the stock level was, say, less than 'half' but not if otherwise.
Still, there can be issue. E.g., the degree of stock level is always relative to the experiments that are ongoing/planned. A user may be ordering an item to use a lot of it, and may not be able to do so if LabStoRe reports 'adequate' supply.
In some sense, human oversight (by a 'manager') will always be needed, not to mention the need for users to be diligent about keeping LabStoRe up-to-date.
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If you can think through these aspects and decide on the best approach, I can help you with any required coding.