Many of us work in cross-functional teams. When you are involved in a project that requires contributions from many different departments, it can be difficult to keep a project moving when different teams have competing priorities. What do you do when you are relying on someone to move a project forward, but it is not at the top of their list?
Commitment dates should be obvious and seem deceptively simple, but don't underestimate their power. A commitment date is a public statement even between only two people.
The most important thing about a commitment date is that it is not soft. It is rigid. You will either meet it or you won't. Publicly failing is not desirable for anyone. If there is a date on the calendar, someone is much more likely to come through than if the agreement is soft. Phrases like "I'll get to it" or "I'll take a look when I have time" are signals you don't have a commitment.
When you start asking for firm dates, it can be uncomfortable at first, but you must remember what you are actually doing. You are not telling someone they will do something by a date; they are telling you! Sometimes there is more power in less pressure. You are not forcing your colleague into any time frame. They are telling you how much time they need and you are simply agreeing. This removes the ability to argue in the future if they fail to deliver.
The power of a commitment date also removes the necessity for explicit authority. If you are a partner on a project, you can't directly control someone else's priorities. The commitment date eliminates this need. Since this is a public agreement, the ball is in their court to follow through. You simply need to check back in when the date arrives.
Try adjusting your language and asking for hard commitment dates on the calendar. You will likely find your team will become a lot more dependable.