Supply chain problems should be defined as experienced by consumers.
It is important that we work on the most important problem constraining the supply chain from reaching its consumer goals. Many-a-times companies define the problem through an internal lens and start solving for symptoms of the problem, instead of its root cause. For example, I have seen them defining the problem as excess inventory or poor forecast accuracy. These are not relevant to consumers and solving them may not benefit consumers in a meaningful way.
On the other hand, problems such as stockouts on retail shelves, stale stocks in stores are real issues relevant to the consumers.
If we define the problem in a wrong way, we may take the wrong path and miss out on the real issue at hand.