Most professionals in the IT acquisition field have experience in preparing the traditional SOW (statement of work) that stresses how the work should be done more so than the desired results. Many are finding it difficult to prepare a PBWS (performance-based work statement), which stresses the results rather than how the work is to be done. Consequently, there are far fewer performance-based contracts than expected. In your view, what is the biggest challenge in preparing a performance-based work statement and what can be done to overcome that challenge?