Ninety percents

I can't find it anymore, what I once read as a rule of thumb for software development that goes something like the following.

The first 90% of a software project is easy. The second 90% of a software project is hard. The third 90% of a software project is where you finally get a good product.

Instead, what I found during my Google search was the following, called the ninety-ninety rule and attributed to Tom Cargill of Bell Labs.

The first 90 percent of the code accounts for the first 90 percent of the development time. The remaining 10 percent of the code accounts for the other 90 percent of the development time.

Both heuristics describe what is common knowledge to experienced software developers: software development is hard. It's hard in a diminishing returns sorta way, and it's hard because somehow these diminishing returns take us a little by surprise in each project.

These days at work I'm somewhere between the first and third ninety percents and firmly behind schedule. So are the other 100+ developers. It's a grind. First I began getting more done without resorting to working more hours. Then that wasn't enough, and I began working longer hours. That's still not enough, so I'm trying to work fewer hours. That's my best answer to the ninety-ninety rule.