Organisations are successful because of good implementation, not because of good business plans. Guy Kawasaki
In business, forethought must go into how a project is to be executed, as its impact on existing business operations could be significant. This is where advance planning can really pay dividends. Developing implementation scenarios and phase plans and then walking designers, operators and safety personnel through these, will tease out issues and risks that can be addressed prior to physical work commencing. It is cheaper and more cost effective to make the changes at this stage than during the construction phase.
Reviewing the execution of a project in conjunction with all relevant stakeholders can result in projects being broken into discrete phases to allow operations to to meet business objectives. These phases can draw out the duration of a project but may also help to reduce its complexity and reduce project and business risk and spread capital spend over multiple years.