Parkinson’s Laws:1st law:
"Work expands to fill the time available"
"Data expands to fill the space available for storage."
Expenditures rise to meet income
Wirth's law:"Software gets slower faster than hardware gets faster".
Moore's law(Intel's co-founder Gordon Moore) the number of transistors on integrated circuits doubles approximately every two years. The period often quoted as "18 months" According to "2010 update to the International Technology" Roadmap for Semiconductors has growth slowing at the end of 2013, and after 2013 "time transistor counts and densities" are to double only every 3 years not 18 months
Last but not least, a very important rule for project management: You can't control what you can't measure.