A manual assembly line is to be designed to make a small consumer product. The work

elements, their times, and precedence constraints are given in the table below. The workers

will operate the line for $400$ min per day and must produce $300$ products per day. A

mechanized belt, moving at a speed of $1\mathrm{.}25$ m$/$min$,$ will transport the products between stations. Because of the variability in the time required to perform the assembly operations,it has been determined that the tolerance time should be $1\mathrm{.}5$ times the cycle time of the line.