• In 1925, R.E. Flanders described the use of product-oriented departments to manufacture parts with a minimum of transportation between workstations, this proposal can be considered the beginning of a technological group.
• In 1937, A.P. Sokolovski proposed that parts with similar characteristics and using similar machinery to manufacture them can be classified in the same group. During the 1960s, this concept was taken up and further developed in the United Kingdom, when J.L. Burbidge developed a system based on this premise, and over the next 20 years Burbidge's ideas spread worldwide.
• In 1959, Soviet Union researcher S. Miltrofanov published his book Scientific Principles of group technology. The book was widely accepted and considered as an inspiration for about 800 plants in the Soviet Union to use technological group by 1965.
• In 1970, the German H. Opitz studied the way parts were manufactured on machine tools in companies in his native country and developed the well-known system of coding and classifying machined parts that bears his name, the Opitz system.

These philosophies triggered worldwide the concept of Group Technology (GT) which are based on the idea that similar products should be made similarly. technological group can not only be applied to parts but can also be used in administrative processes. In the United States, the first implementation of group technology was in 1969 at Langston Division of Harris-Intertype in New Jersey. As a result of this initiative, the company improved productivity by 50% and reduced its downtime from weeks to days.

In this chapter, manufacturing cells will be analyzed, as well as some algorithms for their design.

 

9.1 Manufacturing cell design

Batch manufacturing is considered one of the most common manufacturing systems worldwide, and for decades efforts to improve this process have focused on increasing efficiency and productivity. These advances, coupled with the integration of design and manufacturing functions, were the basis for the emergence of Group Technology (GT). In the following sections you will learn more about these concepts.

Technology groups (TGs) are a manufacturing philosophy in which similar parts are identified and grouped to take advantage of their similarities in design and manufacturing method, this grouping of parts is commonly known as a family of parts (figure 1).

Figure 1. Example of a family of parts

 

Another of the objectives of the technological group is to divide the entire plant into small entities or groups of machines called cells. Each cell is dedicated to manufacturing a set of specific parts. The term of cellular manufacturing it is used to refer to this arrangement of machines.

The connotation of a group of machines refers to an arrangement of two or three machines, and rarely exceed five, a typical manufacturing cell usually contains Computer Numerical Control (CNC) machines, automatic material handling systems, automatic inspection systems and sometimes even several robotic components (industrial robots, autonomous vehicles, among others).

Cellular manufacturing

Cellular manufacturing is an application of technological group in which machines are grouped into cells, where each cell is dedicated to the manufacture of a part or a family of parts, the objectives of cellular manufacturing are similar to the objectives of technological group.

 

The design of the cell is critical in cellular manufacturing, as it will largely determine the performance of the group. The cells used in the technological group can be classified based on the number of machines and the degree to which the material travels between machines, the most common configurations of the cells are the following:

 

Cellular manufacturing is appropriate for medium volumes and varieties of production, if the product has high manufacturing volumes, it is better to consider flexible assembly lines, if the production volume is very low, then it is better to consider simple stations.

To learn about the automation of manufacturing cells, check out the following video:

 

9.2 Binary ordering algorithm

Quantitative analysis of cellular manufacturing

Many quantitative techniques have been developed to solve the problems of technology groups and cellular manufacturing, in this section you will cover the problem from two points of view, the first is to group parts and machines in families; the second is the arrangement of machines within the technology group, to achieve these two heuristics can be applied to solve both problems.

Steps to follow

Example

Click on each step for more information.

 

9.3 Direct clustering algorithm

Steps for its construction

If we index the matrix M(n x m) assigning to the lines the letter i and to the columns with the letter j, we have the following:

1. For each line, calculate the number of positive wi cells and arrange the lines in descending order.
2. For each column, calculate the number of positive wj cells and arrange the columns in ascending order.
3. For each line i =1 through n, move column j to the right if (Mij = 1), maintaining the order of the previous lines.
4. For each column j = m through 1, move line i up if positive (Mij = 1), maintaining the order of the previous columns.
5. If the current matrix is the same as the previous matrix, the algorithm terminates, otherwise return to step 3.
6. Determine the number of cells and their contents.
7. Determine the number of families and their contents.

Example

Matrix of machines (i) and products (j)

 

Click on each step for more information.

 

To learn about the grouping algorithm, check out the following video:

The technological group and cellular manufacturing are manufacturing philosophies that introduced the concept of flexibility in industrial production, before the GT and cellular manufacturing, there were rigid systems such as assembly lines that were oriented to large production volumes, but with very little flexibility.

The technological group focused their efforts on classifying and coding parts according to their characteristics, generating different methodologies for this, such as Optiz. As a result of the implementation of these methodologies, product families are obtained. For its part, cellular manufacturing focused its efforts on designing machine arrays (layouts) that would allow a more agile and efficient manufacturing of the part families.

Technology groups and cellular manufacturing found a very important ally in automation, since the machines that made up the manufacturing cells and that were operated manually evolved to be fully automated machines.

The operators who were responsible for feeding and unloading the machines, including inspecting the parts and products, were replaced by robotic systems and automated inspection techniques.

Imagine if you were hired as a manufacturing engineer in a company that manufactures desktop computers, and you had the responsibility of forming technology groups.

 

Make sure that you:

• Comprehend the concept of cellular manufacturing.
• Create cellular manufacturing systems using the binary ordering algorithm.
• Design cellular manufacturing systems using the direct grouping algorithm.

• Groover, M. (2018). Automation Production System and Computer Integrated Manufacturing (5th ed.). United States: Pearson.

Videos

To learn more about mass production process, watch the following video:

• todos los procesos del mundo. (2022, March 12). Increíble proceso de producción en masa de fundas para teléfonos móviles [Video file]. Retrieved from https://www.youtube.com/watch?v=CNc3-OfiYwA

To learn more about lean manufacturing, watch the following video:

• Convergence Training by Vector Solutions. (2020, May 20). Lean Manufacturing - Pull Systems [Video file]. Retrieved from https://www.youtube.com/watch?v=9OL7BMBa4ys

To learn more about flow systems, watch the following video:

• Eduardo Pérez, PhD. (2020, August 30). L2P1B: IE4355_Facilities_Planning_Flow_Systems_Activity_Relationships [Video file]. Retrieved from https://www.youtube.com/watch?v=hfkdGOFV9bo

To learn more about engineered systems, watch the following video:

• FANUC America Corporation. (2020, July 10). Case Tray Packing and Palletizing System, Courtesy of Kaufman Engineered Systems [Video file]. Retrieved from https://www.youtube.com/watch?v=ML_-GPdVo1Y

Readings

To learn more about the binary sorting algorithm, we recommend reading:

• National Institute of Technology Calicut. (2013). BINARY ORDERING ALGORITHM (RANK ORDER CLUSTERING). Retrieved from http://www.nitc.ac.in/app/webroot/img/upload/Binary%20Ordering%20Algorithm.pdf

To learn more about the direct clustering algorithm, recommend reading:

• Integrated Manufacturing System Class. (n.d.) CH 8 Facility Layout Part 1. Retrieved from http://eng.sut.ac.th/mae/maeweb/sites/default/files/CH%208%20Facility%20Layout_Part1.pdf

Description

From the analysis of a case, the student will apply the binary ordering algorithm to design a manufacturing cell and optimize the manufacturing process involved.

Objective

To apply the concepts of manufacturing cell design by means of the binary ordering algorithm.

Requirements

Read the topic 18.4 Analysis of Cellular Manufacturing from the textbook.

• Groover, M. (2018). Automation Production System and Computer Integrated Manufacturing (5th ed.). United States: Pearson.

Instructions

Read the following problem carefully and solve the questions posed.

1. A mechanical components’ factory has a basic list of products (see Table 1) that are manufactured on a functional production line, as shown in figure 1.

 

Figure 1. Distribution of the production line

 

Product	Operation	Machine
BB-2301	Lathe/Milling	Lathe machine-2 Milling machine-1
EA-1322	Grinding/Turning	Milling machine-3 Lathe machine-1
GB-1202	Lathe/Cutting/Milling	Lathe machine-2 Saw machine-1 Milling machine-1
AB-2202	Cutting/Polishing/Grinding	Saw machine-1 Polishing machine-1 Milling machine-2
DB-3323	Polishing/Milling	Polishing machine-1 Milling machine-1
BB-3431	Cutting/Milling	Cutting machine-1 Milling machine-1
FC-2151	Polishing/Turning/Lathe	Polishing machine-2 Turning machine-1 Milling machine-3
AB-3101	Cutting/Milling	Cutting machine-2 Milling machine-2

Table 1. List of manufactured products

 

 

1. The number of cells.
2. The machines in each cell.
3. The product families to be manufactured in each cell.
4. The difference in time to manufacture all products between the current layout (per process) and the proposed layout (cellular).

 

2. Develop a summary where you present your results including the evidence of the calculations performed. Add a short conclusion on what you learned at the end of the document.

 

Deliverable(s)

Document with the development of the activity and evidence of the calculations performed to obtain the results.

Description

The student will solve manufacturing cell design exercises by applying the binary ordering algorithm and the direct grouping heuristic.

Instructions

Solve the following manufacturing cell design exercises using the binary ordering algorithm and the direct clustering heuristic, in each case obtain the following values.

1. The number of required cells
2. The machines included in each cell
3. The product families to be manufactured in each cell

Exercise 1

Exercise 2