Design elements can have a definite or a variable length:

• Events with definite length: Some design elements have a definite length and cannot be altered within the scheduling process. Most elements such as Count-Down-boards, signations, jingles etc. have a definite length. In this case the Freeze length and the flag Variable are not needed.
• Flexible elements: Other design elements have a variable length to serve to adjust remain times. Their overall length consists of a definite (Freeze-) length that cannot fall below a certain value, and the variable length that can be shortened as desired. Thus, after having determined the freeze-length these promotion elements can be shortened up to a minimum duration such as Teasers. These elements need an activated flag Variable.