I would like to start by explaining how I came to write this
book, and to acknowledge its influences and the help I have
received along the way.
I have been extremely fortunate. I have a wonderful wife and
two wonderful grown-up children, and I have had all but thirty
years working for Shell, which provided an environment that
had stimulating challenges and opportunities to look more
deeply at problems than is often the case.
I first came across computers in 1971. My undergraduate
course was in Chemical Engineering at Leeds University, and
we all had to learn how to write basic Fortran programs in our
first year. I went on to do a PhD, which involved mathematical
modeling of chemical processes and led to my developing an
automatic integrator for stiff ordinary differential equations. As
a result I am probably among a relatively small group of people
who have started a computer by loading the bootstrap program
into memory from the switches to boot up the computer.
I joined Shell in 1978 at Shell Haven Refinery on the north
bank of the Thames estuary, east of London. I was immediately
thrown into the implementation of a computer supervision system
for the Crude Distillation Unit, which monitored the hundreds
of measurements taken around the unit and warned of
deviations from target performance. I spent eight years at Shell
Haven, and while I had a wide range of roles, computers and
computing were a recurring theme. I was, for example, responsible
for the purchase of the first IBM PC on the refinery, and
one of the first in Shell for engineering calculations using a
spreadsheet, and at the time I left the refinery I was responsible
for all the mini-computer based systems on the refinery.