在鱼离开厨房后就变成了基线。它的变更将是正式的，有条件的，高成本的。

--IEEE Std 610.121990 关于基线标准定义
baseline. (1) A specification or product that has
been formally reviewed and agreed upon,
that thereafter serves as the basis for further
development, and that can be changed only
through formal change control procedures.
(2) A document or a set of such documents
formally designated and fixed at a specific
time during the life cycle of a configuration
item. Note: Baselines, plus approved
changes from those baselines, constitute the
current configuration identification. See
also: allocated baseline; developmental
configuration; functional baseline; product
baseline.
(3) Any agreement or result designated and
fixed at a given time, from which changes
require justification and approval.