Evergreening
A policy for keeping resources up to date. Evergreening typically refers tot he process of keeping hardware resources up to date, but the term can also be applied to software and other resources (such as documents). For example a simple evergreening policy might be to replace all computers older than four years with new models. cf "technology replacement", "technology refresh".
An evergreening policy should state whether the purpose is to replace technology to maintain an acceptable level of reliability (mean time between failure), to acquire improved speed and capacity at an acceptable price or a combination of the two (i.e. to acquire the lowest or lower cost technology replacement with speed and capacity at least as good as its predecessor). cf "Technology Refresh" and "Technology Replacement".

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Note added at 1 hr (2011-04-18 12:50:48 GMT)
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I believe in the asker's context, it has nothing to do with patents.

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Note added at 1 hr (2011-04-18 12:51:46 GMT)
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I believe, in the above-mentioned context, it has nothing to do with patents.

التعريف
http://en.wikipedia.org/wiki/Evergreening
وهي استراتيجية تلجأ لها الشركات للتحايل على القانون من خلال تمديد فترة سريان براءات الاختراعات المشارفة على الانتهاء

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Note added at 1 hr (2011-04-18 12:52:55 GMT)
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