Time Core · Contingency Planning · Module

Buffers

Reserve held deliberately and visibly rather than hidden inside individual estimates, where it is consumed without anyone noticing.

The idea

How it works

Padding every task means every task expands to fill its padding, and the aggregate reserve is consumed before anyone notices it existed.

A single visible buffer at the end is smaller than the sum of the individual pads and is actually available, because its consumption is visible.

Working with it

In practice

  1. 01

    Estimate without padding, then add one buffer

    Aggregate reserve is smaller and more effective than distributed padding.

  2. 02

    Make buffer consumption visible

    How much has been used against how much of the work is done. This is the earliest available warning.

  3. 03

    Protect it explicitly

    A buffer that is treated as available time is not a buffer. Someone has to be able to say no.

  4. 04

    Size it from history

    The slippage ratio, rather than a conventional percentage which is either too small or arbitrary.

One level in

The components of buffers

A component is something that exists afterwards which did not exist before — a deliverable or a mechanism, not an intention.

  1. The reserve

    How much buffer is held, and where it sits.

    Learn
  2. The consumption

    How much has been used against progress made.

    Learn
  3. The protection

    Who can release buffer, and who cannot.

    Learn

Buffer consumed against work completed is the earliest warning a project produces, and it is rarely tracked.