Process Flow Diagram for Making a Shirt, with an Additional Worker. Assume the entire process is running at the pace of the bottleneck. Consider only task D, with both workers ironing shirts. What is the capacity utilization for ironing? Refer to the Process Flow Diagram for Making a Shirt, with an Additional Worker. Assume the entire process is running at the pace of the bottleneck. Consider only task D, with both workers ironing shirts. What is the capacity utilization for ironing? 40%