Waltzing With Bears

In this post, I will introduce "Waltzing with Bears" (Tom DeMarco and Timothy Lister) briefly.


  • Valuable projects always have uncertainty (risks).
  • Derivery date and cost tend to be estimated by summing up only planned tasks at the beginning of a project, so delay and cost overrun often happens.
  • It is necessary to provide the orderer with probability distribution diagram (risk diagram) of derivery date and cost which takes into account possibility and effect of risks.
  • To manage risks, continue following actions during the project.
    • Examination -> Estimation of possibility and effect -> Planning mitigation measures and crisis responses -> Monitoring
  • Incremental development is compatible with risk management because it requires to prioritize components.


From my previous experiences, derivery date and cost of first planning are not achieved much more than they are achieved. Every time we fail to achieve them, we discuss insufficient or unexpected things, and discuss what is necessary to improve next. However how many times we repeat this cycle, results remains same as before, and these discussions gradually lose substance.

Taking into account risks in a project feels new to me. This is probably because my company often denies having leeway. If we see risks as probability, it would make sense.

What is important is to consider the effect of failing to achieve derivery date or cost. (Whether it would spoil the project or just need apology.) we should take care of risks according to objective of derivery date and cost.