Fred Brooks: Adding manpower to a late software project makes it later

You can learn more from failure than success. In failure you're forced to find out what part did not work. But in success you can believe everything you did was great, when in fact some parts may not have worked at all. Failure forces you to face reality.

Fred Brooks

faces believe reality

The hardest single part of building a software system is deciding precisely what to build the most important function that software builders do for their clients is the iterative extraction and refinement of the product requirements. For the truth is, the clients do not know what they want. They usually do not know what questions must be answered, and they have almost never thought of the problem in the detail that must be specified.

Fred Brooks

details important want

Present to inform, not to impress. If you inform, you will impress.

Fred Brooks

impress ifs

Nine people can't make a baby in a month.

Fred Brooks

nine baby people

Successful software always gets changed.

Fred Brooks

programming learning successful

How does a project get to be a year behind schedule? One day at a time.

Fred Brooks

one-day-at-a-time procrastination years

Improving your process won't move you from good to great design. It'll move you from bad to average.

Fred Brooks

design average moving

An ancient adage warns, "Never go to sea with two chronometers; take one or three."

Fred Brooks

three sea two

The hardest part of the software task is arriving at a complete and consistent specification, and much of the essence of building a program is in fact the debugging of the specification.

Fred Brooks

arriving learning essence

There is no single development, in either technology or management technique, which by itself promises even one order-of-magnitude improvement within a decade in productivity, in reliability, in simplicity.

Fred Brooks

simplicity technology order

A scientist builds in order to learn; an engineer learns in order to build.

Fred Brooks

scientist engineers order

System debugging has always been a graveyard-shift occupation, like astronomy.

Fred Brooks

astronomy debugging occupation

The complexity of software is an essential property, not an accidental one. Hence, descriptions of a software entity that abstract away its complexity often abstracts away its essence.

Fred Brooks

abstract essentials essence

The bearing of a child takes nine months, no matter how many women are assigned.

Fred Brooks

matter patience children

I have never seen an experienced programmer who routinely made detailed flow charts before beginning to write programs.

Fred Brooks

program flow writing

Show me your flowcharts and conceal your tables, and I shall continue to be mystified. Show me your tables, and I won't usually need your flowcharts; they'll be obvious.

Fred Brooks

obvious tables needs

Well over half of the time you spend working on a project (on the order of 70 percent) is spent thinking, and no tool, no matter how advanced, can think for you. Consequently, even if a tool did everything except the thinking for you - if it wrote 100 percent of the code, wrote 100 percent of the documentation, did 100 percent of the testing, burned the CD-ROMs, put them in boxes, and mailed them to your customers - the best you could hope for would be a 30 percent improvement in productivity. In order to do better than that, you have to change the way you think.

Fred Brooks

cds order thinking

The fundamental problem with program maintenance is that fixing a defect has a substantial (20-50 percent) chance of introducing another. So the whole process is two steps forward and one step back.

Fred Brooks

maintenance fundamentals two

The hardest single part of building a software system is deciding precisely what to build.

Fred Brooks

hardest building software

More software projects have gone awry for lack of calendar time than for all other causes combined.

Fred Brooks

calendars gone time