Re: Practice: Daily Deployment

Adrian:
>But if the users can't get at the features with the 
>UI how does Daily Deployment help?

Two things:

1) Before "going to production" acceptance testing might include actual 
users using the system in a pre-production environment.

2) (and more in line with the practice) If I can deploy daily, I can also 
deploy changes based on feedback daily, So the consequences of any one 
change is very small.

i.e. In practice as deployment deltas shrink, so too does the occurance of 
disastrous consensequences attached to a mistake detectable by customer 
use. Some things (security and performance spring to mind), may have large 
consequences even if fixed the next day, but these are *not* things best 
(or only) detectable via actual use, so the argument still holds. 

i.e. a team that *does* practice daily deployment, does *not* produce 
horrible breaks with expectations such as those found in infrequent 
releases so its ok if the keystone is not tested. This is because a) the 
system's users get used to this level of feedback (because they know it 
can easily and quickly be corrected. Finally, the practicioners get very 
good at knowing what kinds of changes *will* have those consequences, and 
minimize them.

In short, if the change took a day to create, it takes a day to undo (at 
worst) and if I do this every day, I get really good at it, so over time 
my users come to expect this, their reaction to those negative events that 
do occur gets smaller, as does the frequency of their occurance.

Best,
Bill

William E. Caputo
ThoughtWorks, Inc.
http://www.williamcaputo.com
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omnis cellula e cellula