In a guest post titled Successful Products Start with Requirements and Validation on the PTC Integrity blog, Michelle Boucher describes why good requirements management is so critical to product success. Excel and Word tend to be the most common tools used for requirements. They work extremely well for defining requirements, but managing requirements becomes much more difficult. When not properly managed, problems arise. This brings to mind the Seinfeld episode when Jerry reserves a rental car, but then finds there are no more cars. He responds, “You see, you know how to take the reservation, you just don’t know how to hold the reservation. And that’s really the most important part of the reservation: the holding. Anybody can just take them.” Like holding a reservation, it’s really the management of requirements that’s the most important part.