Activity Mapping To Identify Bottlenecks
The cost object under ABC can be products, services, customers, etc. By considering the business process as the cost object, we can prepare “activity maps.” A business process is composed of many activities that work together to add value to a product or service. By using the “activity mapping” technique, the activities in a business process can be mapped in order to determine the flow of a product through the plant [39,51].
Morrow and Hazell state that activity maps are adaptations of the process flowchart technique. They identify two main differences between an activity map and a process flowchart [39]:
1-.An activity map looks at activities rather than at detailed tasks.
2-.A process flowchart looks at the type of task undertaken at each stage, whereas an activity map focuses on the linkages and usage of resources.
In his article “Integrating the Theory of Constraints and Activity-Based Costing,” Salafatinos modified the way activity maps are prepared in order to make them applicable with the TOC. According to him, activity maps must have two important attributes so that they can be used with the TOC: They must illustrate gaps between activities for both overhead and production areas of the company, and they must be able to locate the set of activities that cause these gaps. In his article, Salafatinos suggests using a combination of Gantt charts and dependency grids as a way of activity mapping to ensure that these two attributes are satisfied, and he describes the three steps in preparing and using the activity maps to locate the bottlenecks. These three steps are summarized below [51]:
Step1- Prepare an activity list
Step2- Prepare a Gantt chart
Step3- Prepare a dependency grid
The last step in using activity maps is to find new alternatives and redesign the processes with the longest cycle times. Since Gantt charts and dependency grids portray the linkages between the activities more clearly, managers can identify the bottlenecks more easily and correctly, and increase the throughput of the system by focusing on the right resources.