Cycle time
| Cycle time |
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| See also |
Cycle time is used in reference to time needed to complete one cycle of an operation. In case of production line cycle time can be referred to operation on one machine (e.g. drilling several holes in metal element) or to manufacturing whole complete one product. However, in that case it is more often known as lead time.
Total duration of the work process consists of cycle time of all elements increased by breaks incurred by technological or other reasons. Therefore, total duration of work would consist of:
- cycle time multiplied by number of manufactured elements,
- preparation time * number of elements,
- tools change time * number of changes,
- worker breaks,
- breakdown time.
As only cycle time creates value for the customer, managers try to optimize processes in order to reduce other times. The most popular method is SMED (Single minute exchange of die).
Single Minute Exchange of Die is on purpose reduction of losses in the production process. This method ensure fast and effective way of modification production process from start the current product to start the next product. This quick change causes a reduction production lot sizes and therebody achieves flow improvement.
Duration of the changeover
‘Single minute’ does not mean that all changeovers and startups should last one minute. It means that they can not last take longer than ten minutes (differently from ‘single digit minute’). SMED is the term used to introduce the setup time that can be calculate in a single digit of minutes. It is also called ‘qiuck changeover’. Easy and fast exchange depends on shortening the time duration line or machine from running one product to running the next product.
The need for the variability
In view of demand for product variability, the need to significantly reduce inventories and reduce product life cycles need for Single Minute Exchange of Die and quick changeover programs is bigger now than ever [1].
By the mid-1990s, it was perfectly understandable the meaning of early introduction of new products to both market share. Therefore, the basic condition of constant competition has become reducing time placing the product on the market.
Design Structure Matrix
Product Development Projects (PDPs) are based on information content and methods dominated by them. Therefore, effective time constraint for a product development project requires understanding at first information flow between different project processes. One of the tools that helps understand this is the Design Structure Matrix (DSM).
In this connection, that a lot of time engaged in a complex Product Development Projects is attributable to its expensive iterative nature, next condition is resequencing project activities for efficient implementation [2].
Systems engineering of products, processes and organizations for system decomposition and integration demand tools and techniques. A Design Structure Matrix ensure straigth, dense and visual representation of a complex system. Such a system supports innovative solving the problems decomposition and integration.
Advantages of this technology
The benefits of technology of DSMs compared to alternative system representation and analysis technology have led to their on the increase use in a different contexts such as product development, systems engineering, organization design, project management and project planning.
Types and applications
A Design Structure Matrix can be divided into two types, static and based on time DSMs.
Four DSM applications can be distinguished:
- component-based or architecture DSM, suitable for modeling system component relationships and facititating matching architectural decomposition strategies,
- team-based or organization DSM, favourable for designing integratet organization structures include for team integrations,
- activity-based or schedule DSM, remunerative for modeling information flow between process activities,
- parameter-based (or low-level schedule) DSM, it integrates with integrity low-level design processes based on physical relations of project parameters [3].
Examples of Cycle time
- Manufacturing: Cycle time in the manufacturing industry is the time it takes from the beginning of a production process to the end of the process and the finished product being ready for sale. For example, a car manufacturer may have a cycle time of 30 minutes for each car produced.
- Service: In the service industry, cycle time is the elapsed time between starting and finishing a particular service. For example, a doctor's office may have a cycle time of 10 minutes for each patient visit.
- Project Management: In project management, cycle time is the amount of time it takes to complete a single cycle of a project. For example, a software development project may have a cycle time of 3 months from start to finish.
- Six Sigma: In the Six Sigma methodology, cycle time is the total time it takes for a process to complete one cycle. For example, a restaurant may have a cycle time of 15 minutes for the customer to be served their food.
Limitations of Cycle time
Cycle time has some limitations that should be taken into account when used as a measure of efficiency:
- It does not take into account the quality of the output, only the time it takes to complete one full cycle. Quality issues are not accounted for in cycle time, which can lead to negative results if the quality of the output is not up to standard.
- Cycle time does not include any setup time or other activities that are necessary for an operation, but do not directly contribute to the output. Setup time needs to be factored in to get an accurate measure of the overall time taken to complete the cycle.
- It does not factor in any possible delays or disruptions that may occur during the cycle. Such delays can add considerable time to the cycle, which can be unaccounted for when using cycle time as a measure.
- Cycle time is not applicable in all cases. For example, it is not suitable for services or other operations that are not repetitive. In such cases, other measures should be used to measure efficiency.
Cycle time is often used in a broader context than just production processes. Other approaches to cycle time include:
- Cycle times for product development: In this context, cycle time is used to measure the amount of time it takes to bring a new product to market, from initial concept to final delivery.
- Cycle time for customer service: Here, cycle time is used to measure the time it takes to respond to customer inquiries, complaints, and orders.
- Cycle time for project management: Cycle time is used to measure the amount of time it takes to complete a project, from planning to implementation.
In summary, cycle time is used to measure the amount of time it takes to complete a wide variety of tasks, from product development to customer service. It is an important metric for understanding the effectiveness of a process and for improving efficiency.
References
- Abdelsalam H.M.E., Bao H.P. (2006). A simulation-based optimization framework for product development cycle time reduction, IEEE Technology Management Council, issue 1, vol. 53, p. 69-85.
- Browning T.R. (2001). Applying the design structure matrix to system decomposition and integratuin problems: a review and new directions. IEEE Technology Management Council, issue 3, vol. 48, p. 292-306.
- Browning T.R. (2012). Design Structure Matrix Methods and Applications. Massachusetts Institute of Technology.
- Deenick E.K., Gett A.V., Hodgkin P.D. (2018). Stochastic Model of T Cell Proliferation: A Calculus Revealing IL-2 Regulation of Precursor Frequencies, Cell Cycle Time, and Survival. Journal of Immunology
- Langerak, F., Hultink, E. J., & Griffin, A. (2008). Exploring mediating and moderating influences on the links among cycle time, proficiency in entry timing, and new product profitability. Journal of Product Innovation Management, 25(4), 370-385.
- Sherman J.D., Souder W.E., Jenssen S.A. (2003). Differential Effects of the Primary Forms of Cross Functial Integration on Product Development Cycle Time. Journal of Product Innovation Management.
- Yash D., Nagendra S. (2012).Single Minute Exchange of Dies: Literature Review, Journal of Lean Thinking, issue 2, vol. 3, p. 27-37.
Footnotes
Author: Anna Zuwała
