Lack of resources for Change implementation

Answer:
Changes are, prior to the implementation, assessed, evaluated and authorized. After that comes implementation planning, e.g. who (resources) and when (time plan). So, this is the first moment when you can influence which resources will be dedicated to which change. Later on, once change is ready for deployment, you still have time to manage i.e. prioritize implementation and its schedule. Important is to manage change implementation right from the creation of RfC (Request for Change). read the article "ITIL/ISO 20000 Request for Change – Your steering wheel throughout the change lifecycle" https://advisera.com/20000academy/blog/2015/09/01/itiliso-20000-request-for-change-your-steering-wheel-throughout-the-change-lifecycle/ to learn more.