By occupation, one things I've done is manage software projects. One of multiple similarities I've found between that role and bicycle touring is something project management calls "risk planning".
When I'm doing risk planning more formally in a software project, we'll brainstorm a set of possible things that might go wrong, catalog them with likelihood and probabilities. After that we'll plan out possible responses, particularly for those most likely and highest impact. For some things we take actions to lower the probability, others anticipate a response and yet others we might decide to explicitly ignore the risk...
I find myself doing many of the same steps during a bicycle trip, though not always as formally:
- Roughly in my head I'll figure out some things that could go wrong. Over time I've augmented that list from both personal experience and reading a lot of accounts of others trips.
- Some things seem likely (e.g. flat tires) might affect equipment I bring (e.g. patch kits or spare tubes). Other things that seem less likely (e.g. crank arm snapping) I won't prepare for - though when that happened, I applied a more general contingency (hitch a ride). Similarly I'll be prepared for weather that is 90-95% likely (cold weather gear or rain gear) but when remnants of an Atlantic Hurricane and remnants of a Pacific storm dropped multiple inches of rain - I fell back to a more general contingency (hang out until the worst of the weather passed).
- The types of risks planning and the approach also varies depending on the duration of the trip and particularly how I add some contingency time:
* For a weekend trip, a contingency might simply be to cancel the weekend plans.
* For a trip of a week or so, I will typically include at least one "buffer" day to deal with uncertainties and may also have a "short-circuit" alternative where I can shorten the trip or skip ahead.
* For a trip of several weeks I start to leave some things more open-ended, e.g. sometimes even my return travel date or some alternatives to make a longer/shorter route.
* For a trip of multiple months, I start to switch to a "time budget" approach. For example, going across the Americas for 18-months I knew roughly a "budget" of how far each month would get me to destination in the right season. When I was "ahead of budget", I was more likely to take an extra side trip or take an extra rest day here or there. When I was "behind budget", I would take fewer rest days or side trips. I had some contingencies anticipated but not explicitly scheduled (e.g. trip back to US for equipment swap).
Cycle touring has some uncertainties - and ones that might require a change in plans(*). As much as one might try "risk planning", one can't anticipate everything and sometimes it is better to not have an individual response for every single thing that might go wrong - but instead let it happen and use a more general "time" contingency or adjustment. Over time one figures how to adjust, e.g.
>> During 9/11, I was on a 12-month bicycle tour that was originally planned to include cross-USA, around-Australia, Hawaii, India, New Zealand and thought I had tickets from a ticket broker. The broker went bankrupt and money/tickets went missing. My father worked issues to get $ from the broker - and I re-booked the last part of my year trip - splicing out Hawaii and inverting New Zealand first before India.
>> On a trip to meet TDA in Urumchi, China I inadvertently had an invalid Chinese Visa. I had a little bit of extra time, rerouting my plans to go first to Hong Kong to get a visa and then to western China.
>> This past December, my crank arm snapped. I walked for a while before getting a ride. I took a bus back home to end the trip early. I plan to be back next month to finish the original trip.
>> On a trip around Australia, I was "ahead of schedule" enough that I decided to bike up to Uluru and then take the train back to continue the original circumnavigation.
(*) Some of this might be semantics, since frequently my "plans" explicitly have some contingency in them, e.g. I've added a few rest days without figuring out in advance exactly how I might spend them. So the "plans" include some flexibility in advance.