Why is is necessary for organisation to establish and periodically review their objective?

It is necessary for organizations to establish and periodically review their objectives because things change. Organizations that do not acknowledge or monitor the changes that are happening in their field are likely to become irrelevant. For example, if a commercial fishing company wasn't aware that the fish population they usually fish was dwindling in the places where they usually fish, they would miss the opportunity to change to a new place or a new fish and would eventually go bankrupt. Their competitors who were monitoring the change and adjusting their business accordingly would continue to survive.