As of 1994: Denver airport twice size of Manhattan 10x Heathrow land 3 planes simultaneously Baggage handler is automated 21 miles of steel track 4000 cars moving under computer control shuttles bags among gates, counters, claims for 20 airlines 100 computers networked 5000 electric eyes 400 radio receivers 56 bar-code scanners $193 million to develop whole system Opening was 9-months delayed due to failed software scheduled for October... slipped to Dec... to March... to May by June cost was $1.1 million in interest and op costs Studies show that 2 of every 8 large software projects are canceled Average project overshoot schedule by half larger projects do worse 3/4 of all large systems are "failures" in that they do not operate as intended, or not at all This is after 50 years of development of the SE discipline Our "profession" is as musket-making before the industrial revolution non-specialized no interchangeability max crafsmanship special case production slow, time-consuming You can build a cabin with a few carpenters (me, e.g.) You can build a skyscraper with carpenters Modular components, interoperability is very hard: see #2 California Motor Vehicles horror story in paper see #3 American Airlines reservation system in paper The changing nature of computers is changing programming practices "When computers are imbedded in light switches, you have to get the programming right the first time" Mary Shaw, SEI/CMU Getting right first time is very hard: see #1 DoD Satellite horror story in paper The amount of code in consumer products is doubling every two years (my truck brakes... for example) TVs have 500 Kbytes electric shavers: 2 Kbytes power train in GM cars: 30,000 LOC Conditions change, problems remain the same today the tough issues are RT and distrib. sysy IBM Consulting survey of 24 leading companies making dist.sys 55% cost more than expected 68% overran schedules 88% had to be substantially redesigned Another horror story: FAA replacement air traffic control system > 1 MILLION LOC distributed over hundreds of computers embedded in hardware (radar, etc.) real time safety critical IBM FedSym was chosen to build it in mid 80's (since bought by Loral) FAA expected to pay $500 per LOC developed this is 5x industry average for large projects FAA expected IBM to estimate well cost and schedule FAA expected state-of-the-art review of design to find flaws early finally paid $900 per LOC every line written needed to be re-written at least once didn't even work tests showed the half completed system to be unreliable FAA canceled 2 of the 4 major components, scalled down a 3rd (cost) $144 million has been spent of these failed parts has already spent $1.4 billion on the 4th (central) part: controller workstation software as of 1994 is 5 years late, $1 billion over budget code was examined by a team from SEI/MIT/CMU to see if ANY of it could be salvaged