How much time should we invest on the system?

Usually we face a situation: we knew that we are going to deal with a great among of repetition tasks, and we have limited time to accomplish the mission. So, now we have two options. The first one is that we ignore the fact, and just jump in to start working. The up side is that we can save time because we start early. Another option is to step back and try to create a new tool that can accelerate the further process. Personally, I prefer to invest on tools because it saves more time, especially for the bigger task, that often appear in my daily life (and if you need it, I am happy to help). While in some rare cases, it is better to directly work on the project, in others scenarios we better think twice and make the best use of our creativity and speed up the process by making tools. So what do you think?