Waste of Inventory, as defined by the Toyota Production System, is easier to spot in a manufacturing setting. But in an office it's a little more difficult. Be assured, though, it's there!
 
Some years ago I was consulting with a senior level manager at a local hospital. She had 20 filing drawers in her small office. That's 4 five-drawer filing cabinets. After sorting and purging the contents, she was left with 5 drawers of records which she was required to keep. 15 drawers of papers were shredded and recycled. And once the three empty filing cabinets were removed, it looked like an entirely new office with enough space to add a small table and chairs.
 
Paper represents one of the most common wastes in an office. Are you hanging on to items because you're not sure whether or not they need to be saved? Reviewing your company's retention policies will give you the freedom to either keep or throw the paper that surrounds you. Start today and start out small. Give yourself 10 minutes to open a drawer, remove 2" of papers/files and see how much can be released. 
 
Probably the most obvious Waste of Inventory in an office is office supplies. I confess. I love office supplies. And based on what I've observed in others' offices, I'm not alone. Imagine this scenario: Your employer declares a moratorium on the purchasing of supplies. That's right. No more new supplies until the existing ones have been used up throughout the company. How long do you think it would take until all supplies had been used and the purchasing could resume? To avoid this Waste of Inventory, designate one person in each department to oversee the purchasing and maintenance of office supplies.
 
Another inventory is that of time. It's something we all have equal shares of. Where is your time being wasted the most? Sitting in unnecessary meetings? Processing countless e-mail? Or maintaining complicated tracking systems of projects or products?  
 
Discovering wasteful areas in and around your office will hopefully motivate you to removing that waste and replacing it with more efficient systems and processes.