Software engineering happens to be just such a real-world problem. Meteorology concerns the complex interactions of many simple phenomena. Meteorologists now can make reasonably accurate predictions a few days into the future. Forecasts beyond that are shaky. This is the case even though the individual forces that create the weather can be calculated accurately by college freshmen in Physics 101.
Software engineering is similar.
In isolation, the items that make up a large software system are quite simple. The individual algorithms, file formats, and parameter passing mechanisms of a complex system are likely trivial. Mixed together by the hundreds or thousands, however, they are extremely difficult to control and their interactions are hard to predict. In general, the problems cannot be constrained significantly by limiting the problem statement. We cannot make the medical records or the hospital go away.