I'm not too sure in what context you're referring to, but I'll assume you're asking for reasons why you might want to delay updating software. One reason might

I'm not too sure in what context you're referring to, but I'll assume you're asking for reasons why you might want to delay updating software. One reason might be because of regression, when an update introduces a bug that causes the software to malfunction despite it previously working. It is sometimes wise to let other people try out the update first, and then update if it appears to not be problematic. Another reason might be because the update intentionally breaks compatibility, or removes a feature you need. If the new version of the software doesn't meet your requirements, then you might need to stick to using the older version. This might just be temporary until newer versions of the software meet your requirements once again. You might also need time to assess whether the update compromises the security of your systems (there have been instances when updates have contained malware), or complies with legal or business requirements (the terms of the software licence may have changed). Despite all of that, however, it is imperative that security updates in particular are taken very seriously. In most cases, it is a good idea to install security updates as soon as they become available.