Lead time – throughput time

In lean philosophy, lead time is seen as the key indicator. Lead time is proportional to the level of

> excess production and

> inventory in the value stream.

It is based on the time that a component needs to get from the raw material stage to the customer.

To calculate lead time in ...

... Batch production:

 processing time + transport time + idle time

... Single-piece production:

 Time from order input to operation

The total time it takes for a process to convert a raw

material to a finished quality part

 

The competitiveness of companies depends on whether products and services meet market requirements in terms of time, cost and quality. As the dynamics of the market increase, the importance of the time dimension increases. This means that products have to be developed, manufactured and made available to customers ever faster. The same applies to services of all kinds. The decisive factor here is the so-called lead time, which should be as short as possible.

 

What is the lead time?

The lead time (DLZ) describes the time span for processing orders or for the course of processes between and within companies. According to REFA, the lead time in a work system is referred to as time type TD. You

 

may include scheduled and additional stages and times,

is an important parameter for assessing the quality and performance of processes and work systems,

can be used in a variety of ways, especially to generate key figures,

is determined at REFA for orders (order lead time), process chains and processes (process lead time) and for individual work systems (work system lead time).

What are the components of the lead time?

The lead time in production plants consists of the following components (partly optional):

 

Execution time: Sum of the times of all process segments for carrying out task or order processing in the work system.

Additional time: Sum of the times of all process segments that can occur in addition to the scheduled execution of tasks. If additional times occur regularly, this is an indication of potential for improvement.

Transport time: Sum of the times of all process stages that are used to transfer the order to the following work system, for example, transport time of finished parts from assembly into the warehouse.

Waiting time: Sum of the times of all process sections in which the order waits between two work systems for its further execution, e.g. finished individual parts wait for assembly to the finished product.

Storage time: Sum of the times of all process stages in which parts, semi-finished and finished products of an order are stored in storage areas before, between, or after execution.

How can the lead time be shortened?

Approaches to shorten the lead time are:

 

technical or technological improvements

Avoidance of disturbances

Improvement of workflow and information flow - Process optimization

Balancing the capacities of the resources used and the employees deployed

Information and qualification of the employees involved