In simple terms, a statute of limitations may start to run at a date other than when a wrongful act or omission allegedly occurred, or may be extended based upon factors that delay the reasonable discovery of an injury or the plaintiff's ability to take action, while a statute of repose is triggered by the completion of an act and is not ordinarily subject to extension or exception. For example, many U.S. states have laws that provide that when a construction project is "substantially completed," meaning that just those items on a "punch list" remain, a statute of repose starts to run for claims relating to defective design or construction.