Software is not Efficiency

Searching online and discussing with colleagues, I’ve often found that many people believe that “Software Is Efficiency”. But that’s the wrong way to think about it. Software is not efficiency. It’s just that efficiency is often the desired outcome of building software.

What is software, then? Definitions tend to be incomplete. For example, if we said that “Software consists of computer programs that instruct the execution of a computer”, even if technically true, it would be a stretch of the imagination to think of video games as software. Some might argue that interfaces are separate from software but, in the real world, the physical limits of things are part of things. Interfaces are part of the objects: our understanding of an object cannot be separated from the way we interact with it. The skin is part of a person’s body, the color is a property of an object’s material.

So I will propose an updated definition:

Software is a collection of programs and interfaces built for a purpose.

This definition highlights that interfaces are a key component of software. It makes it easier to see that video games are software, since people play video games to interact with the graphics and sound (interface), without caring about the underlying data. It also focuses on the process (“built”) and the purpose. No software is accidental, and all software is developed with a goal in mind, even if the goal is not stated explicitly. Even if a hobbyist developer wants to build a simple proof of concept, the goal is “to see if something works”. If he wants to build something for fun, the goal is “to have fun”.

A key part of this new definition is that software is built, that is, software construction plays a fundamental role. Like the physical construction of buildings, houses, and bridges, coding is a complex process that can lead to the success or failure of the software.

Construction is the only activity that’s guaranteed to be done The ideal software project goes through careful requirements development and architectural design before construction begins. The ideal project undergoes comprehensive, statistically controlled system testing after construction. Imperfect, real-world projects, however, often skip requirements and design to jump into construction. They drop testing because they have too many errors to fix and they’ve run out of time. But no matter how rushed or poorly planned a project is, you can’t drop construction; it’s where the rubber meets the road. Improving construction is thus a way of improving any soft- ware-development effort, no matter how abbreviated.

— McConnell, Steve. Code Complete: A Practical Handbook of Software Construction. 2nd ed.

The world of software is not like our world. The digital realm has a set of properties that are unlike physical objects in our world.

• You can create exact copies of software without degrading its quality.
• You can radically change a program’s behavior by just changing a single line of code. (Instability)
• Software doesn’t get depleted with use. It can be used indefinitely.
• The cost of building an extra unit of deliverable software (marginal cost) is almost 0.
• Unlike physical goods, software doesn’t get stale or damaged. It doesn’t degrade.
• A given piece of software always produces the same output if given the same initial conditions and inputs.
• Efficiency, sometimes: efficiency is defined as the ratio between the output and input of a process. Software can be efficient if it is faster, produces more value, or uses fewer resources than the previous process that was in place.

But software is not efficiency and building software does not guarantee efficiency. For example, a new digital product might need constant manual monitoring, or it might not be as fast as expected. Modeling processes to build software can also lead to accidental complexity, that is, creating unnecessary abstractions making the code more complex than it needs to be.

The good news is that, when built properly, software is worth it. Digital products built with thought and skill improve processes, save time, reduce risk, and make a more efficient world.