How can you use this? I'll give you a publishing example. In a former (business) lifetime, we wrote auto repair manuals. The major book each year included about 2000 pages to cover all the material, and we had to write those pages in about 5-6 months.
How many people did we need? Now that's a real math question.
We averaged, if I remember properly, about 2 hours per page. That means 4000 hours for that book. Now a single editor worked about 40 hours a week, but didn't WRITE for 40 hours. At best, we got 32 hours out of a 40-hour week.
So 4000 ÷ 32 = 125 weeks to write the book.
For one person. That wouldn't work because we needed this book every year. In fact, we had to do it in about 6 months, because we needed to sell it while that year's cars were still being sold.
There are 26 weeks in half a year - in fact to give ourselves a cushion, we assumed only 25 weeks.
125 weeks ÷ 25 = 5
We need 5 writers and some artists and some proofreaders to get our book finished in 6 months.
Here are "some of the boys" outside the office. I didn't work there then, I was only 13 when this photo was taken. But when we left this building in around 1980, I got the sign off the doorway. It's in my garage somewhere ... Oops I digress.
After some practice we came up with formulas (formulae) for writing our books. We could predict how to write any manual. At least we could until they came up with new-fangled things like front-wheel-drive and electronic fuel injection. All the calculations changed.
One thing I learned was you can't speed up each and every project. No matter what the boss says. Not by putting on more people. Not by working overtime. Some things just take time!
For example, 1. Ladies Shopping
2. Hoping a mountain lion will get bored and get off my porch!
3. Having a baby!