Umen: Again each industry will have their own wants and needs. The type of inventory that a clothing department store needs is a heck of a lot different then the type that a car repair shop needs. I would bet theirs a whole crap load of software for this both ranging from extremely expensive because it auto ties in with your UPC codes, such as a chained store uses, to very basic and free such as you can find at SourceForge.
If this is for any real life company, ACCESS or OpenOffice is not ideal as they (at least access) has some huge flaws. 1) It has cap of how big certain things such as strings or how many rows it can handle 2) It can only be accessed for writing by one person at a time. Unless you are the soul person in your business, theirs a chance 1 or more people might need to access your inventory and update it at once
In reality each and every company should look at their specific wants and needs and find a solution that is right for them. If you have enough inventory that you need to regulate it, you should spend the little money in comparison to make sure it's done right. You usually always get what you pay for in almost every field, and in software that stands true. Theirs tons of free graphic design software out there, but none come close to touching photoshop. You can find dozens of accounting solutions out there for free, but nothing comes ballpark close to QuickBooks. And you can find dozens of free GUI of WYSIWUG web developers out there, but in my opinion, Dream Weaver will always take the cake in usability.