Cycle time

Cycle time
Primary topic
Related topics
Methods and techniques

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[edit]

‘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[edit]

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[edit]

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[edit]

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[edit]

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].

References[edit]

Footnotes[edit]

  1. Yash D., Nagendra S. 2012
  2. Abdelsalam H.M.E., Bao H.P. 2006, 69-85
  3. Browning T.R. 2001, 292-306

Author: Anna Zuwała