I take the bus to work most every day and recently I’ve noticed two new, to me, syndromes. First off I’ve noticed that I catch later of two morning buses it will passes the earlier bus on it’s way. Secondly I’ve noticed that if the bus is even a few seconds ahead of schedule this advantage will accumulate so that it arives at the train station quite a bit ahead of schedule. Both of these have to do with passenger loading delays.
The 2nd bus wins because it is less popular, so it stops less often; while the 1st bus is very popular and has to stop a lot. It’s the passengers, and their loading time.
The second syndrome, where the amount a bus is running ahead of schedule piles up is also due to the passengers. In this case the bus doesn’t have to pickup passengers who come out to the bus stop on schedule. I’ve noticed that when I miss my favorite bus, but I’m on schedule, it will drive by empty – which of of course get’s my goat.
These are interesting complementary syndromes and they suggest that being on schedule is unstable. Early buses tend to become even earlier, since the load they usually carry doesn’t appear; while buses that run late tend to accumulate additional loading costs. It’s fun to think about how one might overlay some regulatory scheme to temper these effects.
Seems to me there is an analagous syndrome in projects. Delayed projects tend to accumulate more items, as the delays allow more requirements to show up and pile-on. Projects ahead of schedule tend to pick up speed as they drive pass additional requirements which haven’t managed to get the meetings on time.
It’s interesting to muse about what interventions one might take in these situations. Driving by a few bus stops to get back on schedule, or explicitly ignoring a few project requriments is very hard to execute on. There is one bus driver on my route who appears to have discovered that he can spend a lot more time drinking coffee if he gets ahead of schedule; the man’s a maniac. I’ve worked with managers like that.
Transperth bus routes have timed stops along the way, where the bus will stop and wait if it’s ahead of schedule. The analogy to delayed projects is correct for Chandler – they added GTD to their requirements not that long ago.