Use Little's Law to speed up your process.
Understand Little's law and how it can be leveraged to resolve bottlenecks in your operational flow paths.
Background: Little's Law is a fundamental principle in operations management. It establishes a relationship between three key variables: cycle time, work-in-process (WIP), and throughput. According to Little's Law, the cycle time of a process is equal to the average WIP divided by the average throughput. In simpler terms, it quantifies the time it takes for any unit (such as an item, job or order) to flow through a process and emphasizes the importance of managing WIP levels and throughput rate. By understanding how data is moving through a process, we get a clearer understanding of where bottlenecks may be occurring and the impact this has downstream.
Design of successful processes and managing them efficiently, requires businesses to fully comprehend how processes differ from one another based on their use case. Understanding the principles behind this can lead to significant improvements in operational efficiency. If we look at the various kinds of operating systems that we design process around they will fall within 2 main categories.
Process Focused Operations:
Sometimes called a job shop, a Process-focused operation utilises smaller kinds of skills, activities, and technologies into separate departments. Products are moved by material handlers from one batch to another. Units get moved by ‘routing’. In the context of maintenance work orders, this may include the movement of assigned work across departments (Example Instrumentation & Control hand off to Electrical). The job shop scenario illustrates a process with multiple specialized workstations. Little's Law helps assess the cycle time by considering the average WIP and throughput of works as they move through each gate/status (https://maxlogic.substack.com/p/understanding-the-concept-of-status ) and get acted upon by the various assigned departments and roles. Through applying Little’s law and analysing your CMMS data, you can analyse which phase gates are causing bottlenecks.
Product focused Operations:
Paced: A series of tasks, performed in sequence / parallel allow production of work. These can be either Worker-Paced Lines with the units batched, as a single piece flow / Cellular Processing or a Machine-Paced Assembly. Little's Law aids in understanding the cycle time by considering the WIP and throughput of any section that may be holding up the flow.
Continuous Flow Process (CFP): CFP is a product focused operation for a specific type of output. The production of electricity by specialized high-capex assets, where workers primarily focus on maintenance, represents a continuous flow process. Little's Law enables the assessment of cycle time by considering WIP (level of assets in operation) and throughput (rate of electricity generation).
Effective process design and management are essential for enhancing overall operational performance. Are you often held up waiting on the release of safety documents ? Are Purchase Orders taking too long to be released once approved? Every industry has these process areas existing that they intuitively know could be sped up and improved but may not know how. Here are some key considerations:
Assess the Process Performance: To improve a process, it must first be understood and assessed. Review the cycle time, WIP, and throughput. Little's Law provides a valuable framework for measuring and evaluating these variables, helping identify areas for improvement.
Balance Flexibility and Cost: Processes offering high flexibility, customization, and a superior user experience come at a higher cost. It is important to strike a balance between meeting the demands of the business and managing costs effectively.
Trade-offs in Process Design: Designing efficient processes requires making trade-offs. Understanding the different process types (e.g., job shop, worker-paced line, machine-paced assembly, continuous flow) helps in making informed decisions regarding the end state.
Aligning Process and Product: In product-focused operations, organizing work based on product families or customer types allows for specialization and improved efficiency.
Use your EAMS/CMMS data: Your Asset Management system should readily have data available to you letting you see which status and roles tend to keep records the longest. Once this is known, regardless of area, a more detailed analysis and optimisation can be undertaken to improve the flow. This may be in the form of process improvements, extending to additional approvals, department bypass if certain conditions aren’t being met, escalations, etc.
Assess your data and process efficacy using Little’s law to make big improvements in your operations.