This interview was provided courtesy of the Computer History Museum.
Grady Booch: So welcome. This is
Grady Booch. I’m here with Watts Humphrey and we’re connecting via Skype
because we’re both in different parts of the world. Here we are on a morning of
Wednesday, June 17 for an oral history on behalf of the
Booch: Twenty years. Oh, my goodness. Time moves quickly, doesn’t it? Wow. Of course I have as much as hair and I’m as virile as I looked 20 years ago,
Humphrey: I can see that.
Booch: So let’s begin. I’m going to start off with just some general philosophical questions here and then want to dive into just your life and how you got to where you are and then we’ll end up with where you think the world is going. You’re often considered by many as -- I think you’re called either the grandfather or the father or the godfather of [software] quality. There are various monikers given to you and, indeed, you’ve been honored by the president by receiving the National Medal of Technology back in -- that was 2003, was it not?
Humphrey: It was the 2003 medal. They actually didn’t award it until 2005. There’d been a few things going on then and President Bush didn’t have time but it was a marvelous event.
Booch: Good, and we’ll talk about that. I mean, you truly have made a seminal difference in the art and the practice of software engineering, especially with regards to elements of quality. So I’m just going to ask a very broad question at first because this has been your life. What is quality and how does one measure it and how would you rate contemporary software systems in terms of quality?
Humphrey: Well, a very general response. Quality is doing the job the way it’s wanted. I agree with Deming’s and Juran’s and the other quality gurus’ definitions. Quality is doing what it takes to truly satisfy the customer.
Booch: My general question to you is, what is quality? How does one measure it and how would you characterize the quality of contemporary software?
Humphrey: Okay. Well, as I mentioned before quality is fundamentally doing -- producing what it is that the user both wants and needs. They’re not always the same and that means in terms of cost and schedule, the way the product you deliver works. It’s defect free. It continues to function properly and it’s a satisfying product and that means we need to really understand what the ultimate customer wants. This is very consistent with the views of Deming and Juran and the whole quality community. I think that’s a very standard definition, and my reaction to the way that the software community has responded to this is that it’s dismal. I mean that, by any measure for any other kind of product, software quality is truly terrible.
Producing quality software is a very difficult and a severe challenge. When you consider the quality of software itself and what it takes to make a high quality product, defects per 1,000 lines of code is one rather simple measure. It’s simplistic but quite useful and five defects in 1,000 lines of code is considered poor quality, at least by me and most quality people. You want to talk about defects per million. However, when you look at software quality in human terms, five defects per 1,000 lines of code is extremely high quality. A thousand lines of code, at least my C++ code, was 30 to 40 pages of listings. Five defects in 30 to 40 pages of listings, when you consider it, that’s tough. And if we want to get not just 5 per 1,000 but 5 or 10 per million, we’ve got to talk about 5 defects in 30,000 to 40,000 pages of listings. The problem is that the whole software community is treating this as if today’s products are high quality work. I mean, they’re really, kind of, looking it over and saying, “Yeah, it looks okay.” The real focus on producing extremely high quality isn’t there. We’re not going to get very few defects per million lines of code by just having people try hard and hope they’re doing it well. The lack of a really serious attack on this problem by the entire community, the academics, the theoretical types, industry is, I think, totally irresponsible. People need to understand that poor quality software work is responsible for just about all of the problems in the software business.
Booch: You used a phrase I’d like to dwell upon which was the human factor. What’s the human cost of bad software?
Humphrey: Well, it’s a terrible job. People are unsatisfied with it. They’re delivering products late at excessive cost. The customers don’t like that. Their management doesn’t like that. Software people are really great people who are doing superb work, and they are treated like failures. They’re failures on the job. I mean, this has been the history in software. You can’t run it. You can’t do a job in software and come out as a hero. Software people don’t do that unless they end up building their own company and so we’re failures. These are some of the brightest people on the planet and they end up failing. And I think the failure is in the way we teach them, the research we’ve done, the background and support we give them and the methods they use. I don’t think we’re doing a proper service for the people that we have and the big frustration I’ve got is that we’ve come up with some ways to attack this problem and they’re not getting any real attention by at least the research and academic communities. People don’t recognize it as important and that’s very frustrating.
Booch: In fact, I want to be certain as we get toward the end of the conversation, do remind me, I’d like to understand your perspective on what we, as an industry, could be doing to make a difference. But I’d like to turn now to how you got there because you have a lifetime of experience that lets you speak with authority on these matters, but you didn’t just get born this way, and I’d like to explore the journey that got you to where you were and the things that excited you about the field and drew you into it. For example, I knew you were a wrestler back in college and -- just curious -- how does an ex-wrestler come to this particular domain? So let’s start at the very beginning because these are parts of your history that I wasn’t able to uncover. Where were you born and when were you born if you don’t mind disclosing your age. I think you’re 29 or something if I’m not mistaken.
Humphrey: Thirty-nine. I’ve
been 39 for almost 50 years now, right. I was born on the Fourth of July,
honest to goodness, in 1927. That’s the year Lindbergh landed. So I’m 82 in
another couple of weeks. So I’m an old guy and my dad was an engineer -- an MIT
graduate -- as is my son, by the way. My dad’s name was Watts Humphrey, as was
his father, and he was a marvelous engineer. He was, as I say, a mining
engineer and actually worked in
I read an article
about why I couldn’t read as a child. I literally couldn’t learn to read and I
struggled and struggled and the school essentially failed me. They said I was
doing terribly. So dad pulled me and my brothers (I have two brothers -- an
older and younger brother) out of school and moved us up to a little town
So I ended up being valedictorian of my class and all that kind of stuff and I was head of everything. I didn’t do well with languages at all but that was always a struggle but other than that -- I mean, I was even editor of the school paper and so I just decided ‘dive in and do it.’ My dad’s view was, “If you want to try it and you’re willing to work at it you can do it.” And that really changed my life, so I really did turn into a success going through that, and it was a marvelous education. I mean, I really learned. I stayed at the same school all the way through high school and then went on. I was admitted to MIT with a scholarship and at Cal Tech with a scholarship and then I went in the navy.
Booch: Wow, I didn’t know that, either. So what city were you born in? I didn’t catch that at the beginning because I knew where you moved to but I don’t remember the city.
Humphrey: I was born in
Booch: Oh, that’s where Kellogg was from if I’m not mistaken.
Humphrey: I don’t think we
were there a year. Then we moved to
Booch: Now, there’s a great story. That’s wonderful.
Booch: And you had two brothers, you said.
Humphrey: Yeah, an older
brother, Phil, who was a curator of birds for the Smithsonian. He’s an
ornithologist and zoologist. He’s retired. Unfortunately, he’s very ill. He was
hit with a bad stroke several years ago. He was a first class jazz pianist. Unfortunately,
he can no longer play the piano, which is really a tragedy, but he’s a great
success. He actually discovered -- I think -- the first new species of duck
discovered in 100 years. He was on the front page of the second section of the
New York Times a number of years ago. He discovered the Steamer Duck down in
My younger brother
William actually went to MIT briefly, and then he was in the Army of Occupation
Booch: So as a teen growing up, what were your passions?
Humphrey: I liked to build
things, and I remember my dad bought me a little Meccano
set, a very beginning Meccano set. I couldn’t have
been more than about six or seven, and he made some comment like, “You build
all of that, and I’ll get you a bigger set if you want it.” I said, “Oh, great.”
So I did. My dad was working in
I guess I lost the train of where I was on the Meccano sets. I got so excited about building this stuff that I’d build everything and demonstrate it to my mother who would check it off in the instructions. I got through all the examples in the instructions in a week so dad said, “Okay,” and he got me the next one. I said, “Well, what’ll you do when I build all of them?” And he said, “I’ll get you the biggest.” So I went through all of them in quick order, built everything in every Meccano set, and I got all the way to the last one, and he even got me that one. And I said, “What’ll you get me if I build all of that?” And he said, “I’ll get you a car.” So I couldn’t believe that. I must have been seven or eight at the time and it took me a while to build all the examples, but I actually did. I finished it. He bought a Model T Ford, an old run down Model T for ten dollars. Can you believe it? What would it be worth today?
Booch: Wow. That’s incredible.
Humphrey: We had a farm. It was an old farm back in an area near a trout fishing club that my dad belonged to. There was a farmhouse there, and we’d all worked on it to fix it up, and we’d all participated in ripping things out and trying to kill the many wasp nests in the walls. We put the car out there, so I never got to do anything with it, but I did learn to drive it. Driving a Model T was exciting. I loved to build things, and after that I got very interested in model airplanes and decided to be a aeronautical engineer.
When I was in high school, my dad went into the army Air Force.
Booch: What year would have this have
Humphrey: This would have been
1941, right after
Booch: How sad. They were probably
considered some important war time kind of thing. I mean, you saw
Humphrey: Oh, yeah, so we contributed to German intelligence I’m afraid.
Booch: Before we get further on this I do have to ask one question. Do you still have any of those Meccano sets from your childhood?
Humphrey: No. We moved so many
times. My dad went into the Air Force in 1941. In the previous summer he drove
us out through the west. He’d been told in ’39 or ’40 that he had six months to
live, and it turned out he outlived the doctor by about 30 years. It was his
medical problems from when he worked in a gold mine in
Booch: I have ask -- a small world
Humphrey: We were at the A Bar
A Ranch which was right by
Booch: Oh, yeah, I know exactly where that is. Oh, my gosh. Small world. Yes.
Humphrey: Yeah, the Fourth of
July I remember we were having trouble getting over one of the mountains
because it was snowed in. My older brother met his future wife there at the
ranch. That’s where she was working for the summer. When we got out to