Search versus filing calculator
Defaults are hypothetical. They are not the empirical study means reported elsewhere in the article.
Calculation
Tsearch=R×ts; Tfile=N×f+R×tf. Break-even R=N×f/(ts−tf), when ts>tf.
Equal success and correction costs assumed. Add failure recovery and required records work separately. Negative file-minus-search effort favors filing on time alone.