NullPointerException

“Unfortunately, the most common metaphor for software development is building construction. [...] Well, software doesn’t quite work that way. Rather than construction, software is more like gardening—it is more organic than concrete. You plant many things in a garden according to an initial plan and conditions. Some thrive, others are destined to end up as compost. You may move plantings relative to each other to take advantage of the interplay of light and shadow, wind and rain. Overgrown plants get split or pruned, and colors that clash may get moved to more aesthetically pleasing locations. You pull weeds, and you fertilize plantings that are in need of some extra help. You constantly monitor the health of the garden, and make adjustments (to the soil, the plants, the layout) as needed.

Business people are comfortable with the metaphor of building construction: it is more scientific than gardening, it’s repeatable, there’s a rigid reporting hierarchy for management, and so on. But we’re not building skyscrapers—we aren’t as constrained by the boundaries of physics and the real world.

The gardening metaphor is much closer to the realities of software development. Perhaps a certain routine has grown too large, or is trying to accomplish too much—it needs to be split into two. Things that don’t work out as planned need to be weeded or pruned.”
― Andrew Hunt, The Pragmatic Programmer: From Journeyman to Master