The IRS said in late March that it will let equipment vendors that keep on hand a pool of spare parts to use in servicing customer equipment claim tax depreciation on them without waiting until the parts are put to use.  However, this only applies where the parts of “rotable.”  That means the vendor replaces a defective part using one from the pool and then puts the defective part into the pool, after it has been repaired, for reuse with another customer.  The IRS announcement is in Revenue Ruling 2003-37.