In your opinion, what is the main function of the Mission, the Vision, and the Values to ensure that the strategic plan is a valuable tool for any organization to establish its future direction, actions, and sustainable competitive advantages?

With the changes in the environment constant how does one ensure that they stay relevant to the goals and objectives as they serve their mission while at the same time keeping the vision, and values in check as they embrace change? In other words, could there be a danger of these guiding principles getting hard set in their ways if they are not reviewed from time to time?