Decision Science Excel Simulation based on Flow Chart

Red Lion Scarves will open several new production facilities during the coming year. Each new production facility is designed to have one quality inspector who checks the knitting of the wool scarves before they are shipped to retailers. The arrival of hand-knot wool scarves to the quality inspection department is variables over the 24-hour workday (three 8-hour shifts).

For the quality inspection department being studied, the scarf interarrival times are assumed to be uniformly distributed between 0 and 5 minutes. This means that any number of minutes in this time range is equally like to occur.

Another probabilistic input in the Red Lion Scarves simulation model is service time, which is the time it takes a quality inspector to check a scarf. Past data from similar quality inspection departments indicate that a normal probability distribution with a mean of 2 minutes and a standard deviation of 0.5 minutes will be appropriate to describe the service (inspection) times for Red Lion Scarves.

A concern is that during busy periods, the shipment of scarves to retailers may be delayed as they wait to be inspected. This concern prompted Red Lion Scarves to undertake a study of the flow of scarves into the quality inspection department as a waiting line (queuing) problem. Red Lion Scarves’ vice president wants to determine whether one quality inspector per shift at each facility will be sufficient. Red Lion Scarves established service guidelines stating that the average delay waiting for quality inspection should be no more than one minute. Note: in this problem, each scarf is a “customer” since the customer is the item receiving the “service” of being inspected.