In the view of the Commission this extension is necessary, as is the extension of the deadline for the Parole Commission. This change would reestablish the time Congress initially proposed for the completion of the work. In addition to logistical, administrative, and personnel matters, the Commission must consider a variety of combinations of circumstances and crimes, numbering thousands, in preparing the guidelines. The Commission also must consider length of incarceration and where incarceration is imposed. It must develop regulations for postrelease supervision, address the issue of concurrent and consecutive sentences, develop policy statements elaborating on the guidelines, and consider the issue of postconviction supervision and revocation. This difficult task requires additional time.