Etiquetas:
Batch of one,
Continuos improvement,
Just in time,
Kan-ban,
Manufacturing methodologies,
Process analysis,
Production engineering,
Production systems,
Pull system,
Push system,
Statistical process control
The techniques used in the “pull” production system
The "pull" manufacturing system is characterized by producing only what is required, minimizing inventory in process. To achieve this end, several particular approaches have been created, such as those described below:
Just-in Time: In which only the appropriate components, at the precise moment they are required, are manufactured.
Kan-Ban: It is a paper record that enforces just-in-time, moving with each batch of components. This can be automated using barcodes, QR codes, etc.
Manufacturing cells: Combine the requirements of a variety of products so that a set of equipment can produce each of them, as needed. This mainly applies to manufacturing and sometimes to assembly.
Batch-of-One: Refers to the ability to make any combination of items with a batch size as small as one.
Continuous improvement: Refers to the ability to find ways to improve current processes, often by combining and/or eliminating manufacturing activities.
Statistical process control: Referred to monitoring how well the process is working.
The manufacturing process had played a secondary role in product design for most of the 20th century, resulting in many problems when it came to manufacturing the products. While major aspects of manufacturing processes have been researched and implemented in physical devices for many years, the assembly process had very little beyond the rules of thumb to guide it.
Ideas for improving assembly capability and for designing cost-effective manufacturing systems only began to flourish in the late 1970s. During this period, many individuals and companies began to realize that the most rational course of action involved design. of products and the design of manufacturing systems together, which is called concurrent engineering or simultaneous engineering. A more recent term, which involves the entire company as well as suppliers and customers, is known as collaborative engineering.
Manufacturing methodologies – the pull and push systems
Traditionally, there has been a clear separation between the creation of a product and the means through which it is produced. In much of the 20th century, manual production methods were used in different processes, especially those in which assembly was present. However, many important design decisions were worked on behind a desk.
Between the late 1970s and throughout the 1980s, manufacturing industries of all types and sizes wanted to know how they could replace their manual production methods with better processes. In this way, large companies that produced larger volumes of a product determined that automation was the best solution. In this way robots and other programmable machines were developed. Manufacturing plants of this era were characterized by having work-in-process inventory that took up large amounts of space, creating significant costs that did not generate revenue.
In the 1990s, up to the present day, industries of all sizes need to be agile and flexible, so a new paradigm in the field of production was introduced. This approach means that companies are looking to have the ability to respond to any customer very quickly, while minimizing their costs. Thus, the production philosophy changed from making a stock of some product to manufacturing on demand, which required rethinking the way in which production processes should be carried out.
In this framework, Toyota introduced the approach of producing only what is required, with which the "pull" method replaced the "push" method.
In the “push” production method, each stage of the manufacturing process ran at the highest possible speed, regardless of what happened in subsequent stages, which meant having significant batches of inventory in process. To optimize these processes, elaborate simulation methods were created.
In the "pull" method of production, each stage of the manufacturing process works only when the next stage provides notice that it requires inputs. Viewed another way, each step in the process has a customer, either internal or external, to which it responds. Using this system, inventories in process are minimized, being completely eliminated in many cases. The analysis of such a manufacturing system is much less complex than traditional simulation methods.
Producing only what is required is a fundamental concept of "pull" manufacturing systems, which minimizes in-process inventory. Work is not done in any area until the next level says it is ready for input.
Methods design, motion and time study
What’s methods design
Methods design is the analysis of the various ways a task can be done so as to establish the one best way. It includes motion analysis (the study of the actions the operator can use and the advantages and/or disadvantages of each variation) and standardization of procedure (the selection and recording of the selected and authorized work methods).
While ‘‘time and motion study’’ is the more commonly used term, it is more correct to use ‘‘motion and time study,’’ as the motion study to establish the standard procedure must be done prior to the establishment of a standard time to perform that work.
Motion study definition
Motion study can be defined as “the analysis of the manual and the eye movements occurring in an operation or work cycle for the purpose of eliminating wasted movements and establishing a better sequence and coordination of movements.”
Time study definition
Time study can be defined as “the procedure by which the actual elapsed time for performing an operation or subdivisions or elements thereof is determined by the use of a suitable timing device and recorded. The procedure usually but not always includes the adjustment of the actual time as the result of performance rating to derive the time which should be required to perform the task by a workman working at a standard pace and following a standard method under standard conditions.”
Attempts have been made to separate the two functions and to assign each to a specialist. Although motion study deals with method and time study deals with time, the two are nearly inseparable in practical application work. The method determines the time required, and the time determines which of two or more methods is the best. It has, therefore, been found best to have both functions handled by the same individual.
Methods engineering and workplace design
Workplace design
Material usually flows through a facility, stopping briefly at stations where additional work is done on it to bring it closer to a finished product. These workstations, or workplaces, must be designed to permit performance of the required operations, to contain all the tooling and equipment needed to fit the capabilities and limitations of the people working at them, to be safe and to interface smoothly with neighboring workplaces.
Human engineering and ergonomic factors must be considered so that all work, tools, and machine activation devices are not only within the comfortable reach of the operator but are designed for safe and efficient operation. A workplace chart which analyzes the required actions of both hands is an aid in workplace design.
Methods engineering and Process analysis
Methods engineering definition
Methods engineering is concerned with the selection, development, and documentation of the methods by which work is to be done. It includes the analysis of input and output conditions, assisting in the choice of the processes to be used, operations and work flow analyses, workplace design, assisting in tool and equipment selection and specifications, ergonomic and human factors considerations, workplace layout, motion analysis and standardization, and the establishment of work time standards.
A primary concern of methods engineering is the integration of humans and equipment in the work processes and facilities.
What’s Process analysis?
Process analysis is that step in the conversion of raw materials to a finished product at which decisions are made regarding what methods, machines, tools, inspections and routings are best. In many cases, the product’s specifications can be altered slightly, without diminishing its function or quality level, so as to allow processing by a preferred method. For this reason, it is desirable to have the product’s designer and the process engineer work together before specifications are finalized.
