A list created to create an application monitor the risk exist in the organization. Need a columns displays how long does the items for this list is being opened based on the Created date for the item. Please advise.
You could create a workflow that runs on change. When the workflow runs, it checks for a status of a field, and does a date comparison.
Or if you want live data, I would create a JSLink that runs on your list view. You could grab the created date field, do some quick math using JavaScript and put the value into a new field.