'''Event processing''' is a method of tracking and [[data analytics|analyzing]] (processing) streams of information (data) about things that happen (events),<ref name=LuckhamD>{{cite book|last=Luckham|first=David C.|title=Event Processing for Business: Organizing the Real-Time Enterprise|url=http://ee.stanford.edu/~luckham/|publisher=John Wiley & Sons, Inc.|___location = Hoboken, New Jersey|year=2012|page=3|isbn=978-0-470-53485-4}}</ref> and deriving a conclusion from them. '''Complex event processing''', or '''CEP''', isconsists eventof processinga thatset combinesof dataconcepts fromand multipletechniques sources<ref>{{citation|last=Schmerken|first=Ivy|title=Decipheringdeveloped in the Mythsearly Around1990's Complexfor Eventprocessing Processing|url=http://www.wallstreetandtech.com/datareal-latency/207800335|publisher=Walltime Streetevents &and Technology|date=Mayextracting 15,information 2008}}{{Deadfrom link|date=Julyevent 2019streams |bot=InternetArchiveBot |fix-attempted=yes }}</ref> to infer events or patterns that suggest moreas complicatedthey circumstancesarrive. The goal of complex event processing is to identify meaningful events (such as [[business opportunity|opportunities]] or threats)<ref name=Bates>{{citation|last=Bates|first=John|title=John Bates of Progress explains how complex event processing works and how it can simplify the use of algorithms for finding and capturing trading opportunities|url=http://fixglobal.com/home/secrets-revealed-trading-tools-uncover-hidden-opportunities/|publisher=Fix Global Trading|accessdate=May 14, 2012}}</ref> in real-time situations and respond to them as quickly as possible.
These events may be happening across the various layers of an organization as sales leads, orders or customer service calls. Or, they may be news items,<ref>{{citation|last=Crosman|first=Penny|title=Aleri, Ravenpack to Feed News into Trading Algos|url=http://www.wallstreetandtech.com/articles/217500395|publisher=Wall Street & Technology|date=May 18, 2009}}{{Dead link|date=July 2019 |bot=InternetArchiveBot |fix-attempted=yes }}</ref> text messages, social media posts, stock market feeds, traffic reports, weather reports, or other kinds of data.<ref name=LuckhamD /> An event may also be defined as a "change of state," when a measurement exceeds a predefined threshold of time, temperature, or other value.
Analysts suggesthave suggested that CEP will give organizations a new way to analyze patterns in real-time and help the business side communicate better with IT and service departments.<ref>{{citation|last=McKay|first=Lauren|title=Forrester Gives a Welcoming Wave to Complex Event Processing|url=http://www.destinationcrm.com/Articles/CRM-News/Daily-News/Forrester-Gives-a-Welcoming-Wave-to-Complex-Event-Processing-55492.aspx|publisher=Destination CRM|date=August 13, 2009}}</ref> CEP has since become an enabling technology in many systems that are used to take immediate action in response to incoming streams of events. Applications are now to be found (2018) in many sectors of business including stock market trading systems, mobile devices, internet operations, fraud detection, the transportation industry, and governmental intelligence gathering.
The vast amount of information available about events is sometimes referred to as the event cloud.<ref name=LuckhamD />
