Undid revision 628216286 by Krauss (talk) First it breaks the way opening paragraphs are to start. Second, that's not a correct definition a "bug regression" is not a common term.
The word "regression" (in the term "software regression") is short for "bug regression", a bug that was reintroduced by a subsequent change. TechnicallyA '''software regression''' is a [[software bug]] which makes a feature stop functioning as intended after a certain event (for example, a system upgrade, [[Patch (computing)|system patching]] or a change to [[daylight saving time]]).<ref name=ibm-locating-bugs>{{cite web|last1=Yehudai|first1=Amiram|last2=Tyszberowicz|first2=Shmuel|title=Locating Regression Bugs|url=http://www.research.ibm.com/haifa/Workshops/verification2007/present/Dor_Nir_web.pdf|website=Research.IBM.com|publisher=IBM|accessdate=24 June 2014}}</ref> A '''software performance regression''' is a situation where the software still functions correctly, but performs slowly or uses more memory when compared to previous versions.
Regressions are often caused by [[Hotfix|encompassed bug fixes]] included in [[software patch]]es. One approach to avoiding this kind of problem is [[regression testing]]. A properly designed [[test plan]] prevents this possibility before releasing any software.<ref>{{cite book |last=Richardson |first=Jared |author2=Gwaltney, William Jr |title=Ship It! A Practical Guide to Successful Software Projects |url=http://www.pragprog.com/titles/prj/ship-it |year=2006 |publisher=The Pragmatic Bookshelf |___location=Raleigh, NC |pages=32, 193 |isbn = 978-0-9745140-4-8 }}</ref> [[Automated testing]] and well-written [[test case]]s can reduce the likelihood of a regression.