Have you ever promised solutions or results you couldn't deliver? Have you ever seen a coworker do this? I know I have. When somebody asks if you can solve a problem, the natural response most people want to give is: "yeah, sure, I can do that for you." Understandably, we don't want to say no to peers, bosses and clients. But this doesn't mean we have to set bad expectations from the start.
Early in my career working in Apple retail, I learned a valuable lesson that I find hugely important in the professional world: under promise, over deliver. Now I know some people might say, "Jay, that just sounds like you're setting the bar low so you can run over it and make crappy work look good." But that misses the point. The fundamental purpose of this rule is to properly manage expectations. If you sell somebody the moon and come back with a bucket of dirt, they're not going to be very happy. Even if that person was super excited to initially hear that you could deliver the moon, the only thing they're going to remember is that you gave them a bucket of dirt.
In the world of technology, managing expectations is supremely important. When people are relying on your work to drive their business, setting bad expectations not only damages your reputation. It also hurts their bottom line. There is always pressure to move quickly when solving problems, but that shouldn't stop you from taking the time to properly review and research your options first. Sometimes this means spending an extra hour or two to provide an answer. Other times, you may need to spend several days or weeks before setting expectations about what can be accomplished. A well planned solution will ensure that your customer's business isn't negatively impacted and will often lead to results that exceed expectations.
Of course tempering expectations can be challenging up front, but the net result will always be more positive. If you get pushback on not promising a solution immediately, make sure to explain the purpose of your process and why it benefits the customer. You will never find a stakeholder who's disappointed when your work outperforms their expectations. Everybody will be happier if you under promise and over deliver.