Scheduling New Workers and Choosing a New Work Schedule

How many of each type of worker should AAD hire?
Compare the old schedule that includes overtime on weekends for the regular workers to the new schedule. How much is the company saving?
If the company could find only ten qualified part-time workers and six new hires, what would be the configuration and cost?

Problem

In Indiana where AAD is located, the company has access to a good labor force, and business is growing. The employees work on Saturdays and Sundays to get the jobs finished. Dashiell is planning to start an extra work schedule to accommodate this new increase in business.

Roger worries about quality, while Dashiell is concerned about the cost of each hour of time for each worker and the efficiency of the whole operation. When one of his employees cannot come to work for a day, it causes scheduling problems. Sometimes, they try to find another worker with the same skills and reassign that worker to try and complete the missing employee's work for the day, but it is difficult to replace skilled workers on short notice and expect all the work to get completed. Usually some work has to wait until the following day. When the absent worker returns the next day, he complains that his work was done by someone else and that the job was inferior to what he could have done. This 'posturing' contributes to low morale and inefficiency because it wastes time. Overtime is costly and yet waiting is a delay that can effectively stop the entire manufacturing process.

The 30 regular workers are paid an average of $18/hour, with Saturdays paid at time and a half pay and Sundays at double time. As the required output increases, it is estimated that the average week will soon require about 480 hours of overtime, the equivalent of two weekend days for the whole workforce. Some regular workers are working 16 hours overtime (at time and a half) on Saturday and double time on Sunday, an unacceptably expensive approach.

Instead of continuing to work the regular workforce all week and then paying them overtime as well, Dashiell is considering adding either part-time or permanent workers or a combination of the two. Part time workers would be paid $9/hour and permanent new hires would start at $12/hour. Either type of worker can be trained quickly to perform riveting and light assembly.

There are the following limitations on the application of this new labor:
• Part-time workers at AAD customarily work 20 hours or less per week. Fifteen qualified people are either already working or have been identified, but additional candidates are scarce.
• Only ten prospective new hires are available.

In addition, there are the following potential limitations as well:
• Machine availability when two people need to use the same machine
• JIT parts
• Resource skills; workers with multiple skills
• Market opportunity