When we time an approval process, the actual decision almost never takes long. What takes long is the file waiting: on a desk, in an inbox, or in a folder somebody forgot to check because they were travelling. The delay is not judgement, it is logistics.
The fix is rarely a complicated approval engine. Most of the time it is three things: the request routes to the right person automatically, that person gets a notification instead of having to check a shared folder, and there is a visible queue so a stuck request is obvious rather than invisible.
What we build first
We usually start with a simple sequential approval, one step at a time, with an automatic reminder if nothing happens in a set number of hours, and an easy way to delegate when somebody is away. That alone removes most of the delay, before anything more advanced is needed.