Design of a comprehensive methodology for the lean manufacturing implementation in the colombian context

Abstract: 
Introduction: This article is the product of the research "design of a comprehensive methodology for the implementation of lean manufacturing in the Colombian context", carried out during the years 2019, 2020 and 2021 in Bogotá, Cundinamarca. 
Problem: Existing Lean Manufacturing implementation methodologies do not take into account the organizational aspects of the culture of the country in which it is being developed, thus making its full implementation difficult. 
Objective: Propose a comprehensive implementation methodology that allows increasing the successful application of Lean Manufacturing in the Colombian industry. 
Methodology: This article presents the review and analysis of the existing implementation methodologies and the results of the analysis of problems in implementation processes in the Colombian industry, as well as the comprehensive implementation methodology designed. 
Results: To achieve the successful implementation of lean manufacturing in the Colombian context, an adequate follow-up of the implementation process is required, the commitment of the company's senior managers, the definition of appropriate leaders for the implementation process and the adequate training of personnel. 
Conclusion: This project seeks to propose a flexible methodology that adjusts to organizational conditions. 
Originality: This research integrates key success factors associated with the Colombian context in the implementation methodology. 
Limitations: The sample size of the diagnosis of the degree of implementation of Lean Manufacturing in the Colombian industry from which the key success factors to be included in the methodology are taken.


INTRODUCTION
Globalization has managed to make companies adopt technologies that allow production costs to be reduced, improve productivity and flexibility, broadening their value chain by optimizing resources and activities. This is because resources are not being used efficiently and most of the activities carried out are not sufficiently effective, as they generate waste, which creates problems that result in higher costs.
As the contemporary market is becoming increasingly competitive worldwide, manufacturing organizations are under immense pressure to pursue operational excellence and improve their performance in order to reduce their costs and provide higher quality products in shorter time frames. Lean manufacturing principles and techniques have been widely used by manufacturing organizations to gain a e-ISSN 2357-6014 / Vol. 17, no. 3 / september-december 2021 / Bogotá D.C., Colombia Universidad Cooperativa de Colombia competitive advantage over their rivals [1]. Lean manufacturing is an approach to manufacturing management that strives to make organizations more competitive by increasing their efficiency and decreasing costs by eliminating non-value-added steps and inefficiencies from the process [2]; [1].
Lean Manufacturing tools are independent, but they have a common goal; they seek to improve profits and eliminate as much waste as possible. These tools contain basic guidelines for their implementation, but it is essential that at the time of implementation not only the theory alone is understood, but also the particular processes of each company and the necessary adjustments are made to ensure the success of its implementation. This requires constant adaptation and learning [3], especially in Colombian companies where cultural behavior directly affects their improvement systems.
The Colombian manufacturing industry is no stranger to the need of remaining competitive at a global level since the import and export index in Colombia increased 8.5% in annual percentage average from 2001 to 2019 [4]. Colombian companies, in their eagerness to be competitive and meet the needs of their customers, have innovated processes to reduce production costs, increase productivity, improve flexibility and expand the value chain, among others. Likewise, changes have been observed in relation to social and institutional aspects, which go beyond the company itself, and these have adopted philosophies that allow the continuous improvement of all the links that make up its value chain.
One of the main objectives in strategy formulation and implementation is the creation of sustainable advantages for companies. De Oliveira and Fensterseifer [5] argue the need to understand why some companies perform better than others operating in similar market and competitive situations. These performance differences can be attributed to differentiation in internal factors, such as knowledge and other strategic assets, which have an impact on the overall company's performance. This mindset is embodied in the "Resource-Based View" (RBV) approach that considers companies as different amalgamations of both productive and strategic resources as well as capabilities that lead to different performance potentials.
Since each company has its characteristics, it is viable to design a production management model that includes the fundamental theoretical concepts and the variations required to achieve an implementation methodology tailored to the needs of each company. Therefore, with the objective of adapting the principles, approaches, and tools of Lean Manufacturing to the Colombian context, the idea of proposing a methodological process that takes into account pre-existing methodologies and suc- Therefore, in order to support Lean Manufacturing implementation processes, this work presents a methodology for Lean Manufacturing implementation that understands each company's particular processes and adapts to them to guarantee its successful implementation in the Colombian industry.

Literature review or research background
A systematic literature review involves the study of selected articles searched in different databases and sources [6]. According to Hong and Easterby-Smith [7], the literature review is a necessary step in structuring a field of research and progressing our understanding of any emerging research area.

Methodology
In order to search for information related to the review of the state of the art, the following keywords were established: methodology, lean manufacturing, implementation, and Colombia. The following electronic databases were used to search for information: Sciens Direct, Taylor & Francis Online, Sage, Oxford, Scielo, and Dialnet Two search processes were carried out between 1999 and 2021; in the first process the words: methodology, Implementation, and Lean Manufacturing were used and a total of 19,646 results were identified in databases; in the second process the words: methodology, Implementation, Lean Manufacturing, and Colombia were used and a total of 750 results were identified.
Within the results obtained in the two search processes carried out, it was possible to identify that there is a great variety of information related to the subject and that this has increased in the last 10 years, as shown in the graph below.

Reference: the authors
A pre-selection of articles presenting information on Lean Manufacturing implementation methodologies in the title, summary, or keywords fields was made from the totality of the results obtained. Then, articles that could be repeated in the 6 databases consulted were eliminated. A total of 29 articles were identified in this exercise.
Finally, each of the selected articles was read from the abstract, followed by the introduction and general reading to determine if it described the Lean Manufacturing tools included in the implementation methodologies and the general aspects to develop a successful implementation methodology. In this last step, a total of 18 articles that could serve as a reference were identified.

Lean Manufacturing
The term "Lean" was introduced by a study group of the Massachusetts Institute of Technology to analyze the manufacturing methods of companies in the automotive industry worldwide [8], this philosophy emerged as Toyota's Production System (TPS) in 1950 [9]. Its main objective was to carry out operations with minimum cost and zero waste [10]. The TPS is represented by a house whose foundations are given by operational stability and continuous improvement. The walls, on one hand, are represented by the Just In Time system: "the right part, at the right time, in the right quantity" [11]; and on the other hand, the quality in the process, or "Jikoda" is stated with the control of line stops, poka-yoke, visual factories, efficient work, and machinery. With these foundations and walls, we have the house's roof, which represents high quality, lower cost, and shorter delivery time goals.
In Colombia, the context of incorporating the model of economic openness to gradually incorporate into their production processes the administrative and operational adjustments that enable them to meet the quality requirements and gain share in international markets [12].

Lean Manufacturing Implementation Methodologies
Regarding implementation methodologies, the literature is very vast; however, we will try to describe some of them, showing their techniques and results. The first one is the one proposed by Carreras and Sanchez [13], in which they suggest a model dividing it into three levels: Second level: Group identified key aspects, classify them under each key factor, and prioritize them for each of the phases in which a company is in the implementation process.
Third Level: Defining the strategies/good practices for each of these key aspects to follow in order to achieve a consolidated Lean implementation. The first is associated with the vital aspect defined by the commitment of the management, for which it was determined that all Lean implementation must be endorsed by the support and for monitoring the implementation of the Lean strategy; and the third focuses on the visualization that should be given to the company as a value chain so that each department's objectives become common objectives, which leads to a radical change in the functional structure.
In this model, pre-operation is given special treatment, meaning that before implementing any Lean practice, the important thing is the motivation from management, the company's size, the determination of the complexity of the process, and the recognition of management's expectations. In this way, according to the proposed model, the implementation of Lean is not a short-term strategy but becomes a habit of continuous improvement. [13] The implementation of the Lean methodology is extremely interesting and good contributions have been made for its implementation. The Massachusetts Institute of Technology (MIT), in a collaboration program they have with the US Air Force, presents a model that describes 7 phases with its main components or actions in order to make the transition to a Lean-type company [14]. The methodology is cyclical, which evokes providing us with metrics that respond directly to each of the 12 points to track in the methodology. The Enterprise Lean Model, unlike the previous one, which was used to initiate the implementation of Lean, is used more to refine and make processes work better based on Lean concepts.
It is also possible to identify 5 basic steps to have a Lean process [

1.
Defining what adds value in a given process.

2.
Identifying the value stream, the chronological flow of how the process activities add value since people are visual by nature and can place the value activities when they can see their process flows.
3. Forcing activities to flow without interruption. Any non-value adding activities should be removed or minimized (in the case that non-value adding activities are required the impact to the process is minimized).

4.
Enabling the customer to pull the product or service through the process.
5. Continually strive for process perfection by reviewing the above steps again to form a cycle and continually ensure that the process is improved.
Jing [18], in a conference for the IIE (Institute of Industrial Engineers), summarized the Lean methodology. This methodology shows how the tools are common to others previously presented, and the event called Kaizen stands out because it is under its continuous execution that improvements are produced in the organization.
The so-called Lean Production System is consolidated by applying most of these tools, being interdependent with each other. Arrieta, Muñoz, Salcedo, and Sossa designed a scheme that allows seeing the general effects of the implementation of different Lean Manufacturing tools in the Colombian Industry. [19].
According to Herrera, Herrera, González [20] various authors have shown the usefulness of lean tools in improving productivity, which is why it is necessary to identify the various implementation methodologies and the tools that were used in each one of them.
The following is a comparison of the research articles related to the development of Lean Manufacturing implementation methodologies. Table 1 shows the title of the article or document, the authors, the tools used in the implementation methodology designed, and whether organizational aspects are included in the methodology or not. Azevedo, J., Sá, J., Ferrerira, L., Santos, G., Cruz, F., Jimenez, G. and Silva, F. (2019) [36].

Considers Organizational Aspects
Lean manufacturing model for production management to increase SMEs' productivity in the non-primary manufacturing segment.

5´s, KANBAN Considers Organizational Aspects
Methodology design to incorporate Lean Manufacturing tools in risk management in order to reduce occupational accidents in service companies. The organizational aspects identified in the different methodologies are related to the organizational structure rather than to the strategic guidelines or the organizational culture factors.

Lean Manufacturing in the Colombian Context
Colombia was a late starter in the implementation of Lean Manufacturing tools within companies. According to Arrieta, Botero, and Romano [39], only implementation in the textile sector and in the industrial sector [40], found that companies have not developed a Lean culture and philosophy, and therefore, the use of tools is reduced.
The least implemented tools are the Electronic Document or Information Exchange were the ones that made this study possible. Initially, they were contacted and only 7 companies agreed to participate. The survey was conducted by telephone with those directly responsible for the Lean tools' implementation process, who were familiar with it, its results, and the problems encountered during its implementation.
The survey was based on one previously applied by Leon, Marulanda, and Gonzalez [42] with some variations, this one has four sections.

Company's general information, Lean Manufacturing implementation sta-
tus, tools applied, and benefits achieved.

2.
Monitoring and control strategies information that enabled the implementation of Lean Manufacturing.
3. Requirements and characteristics prior to Lean adoption.

Problems encountered during Lean Manufacturing tools' implementation.
With the information collected, data was tabulated and the important and recurring aspects of successful implementations were identified. This information was supported by related bibliographic sources.

Results
Each of the companies surveyed had a variety of tools implemented, according to their particular needs. Not all the tools were implemented in their entirety, but they were implemented in some of the company's processes. In this particular exercise, the visual factory was identified as the most generalized tool, followed by 5S's and Manufacturing Cells, as can be seen in Table 2. Indicators must be managed to monitor and control the project's progress, as they are necessary to evaluate the implementation's efficiency and effectiveness.
Awareness and training processes are vital during the project's implementation; they should be carried out with the support of the organization's leaders to ensure the philosophy's adoption and appropriation.

RESULTS
A comparative table was developed as a result of the above reviews, comparing the lean manufacturing tools included in the research articles and those implemented in the surveyed companies.

Full Management Support
The first step in this methodology, or steps to follow for the Lean implementation in the organization, is to have the unconditional support of the company's management. Illustration 4. The importance of the initiative for the organization.

Reference: the authors
As can be seen in Illustration 4, it is crucial to analyze where the organization is in relation to the initiative being taken. It is desirable to be at least in the lower left box, where the initiative is important to the business and therefore has 100% support from top management. To have a point of reference: Toyota would be in a great position in terms of the Lean initiative since they are pioneers of this production system.

Leader Appointment
Leaders play an extremely important role within organizations for implementing Lean at different company levels. To apply this methodology it is necessary to modify the organizational structure and create positions to lead and manage the implementation process.
The general leader of the process must have the knowledge of the tools, and their leadership is essential. These are the leader's main functions: • Defining the vision and how to get there. (Strategy) • Knowing that 85% of Lean Manufacturing is leadership is of utmost importance, the remaining 15% is nothing more than the correct application of the concepts.
• Adapting their behavior according to the working conditions, equipment, organization, etc. • Learning with their team in the workplace (better known as Gemba by the Japanese) is also important for the leader to learn with their team.
• Using the tool of the ("5 whys") which consists of asking why 5 times in each situation.
Pick the Internal Team.
There are different models for work team selection; among them Gordon Raber mentions a series of steps that are important [43]: 1. Stating the requirement.
2. Analyzing the profiles that are needed.

4.
Interviewing the candidates.5. Selecting the candidate for the team.
The team is critical to the success of the initiative within the organization. It is recommended to form a working team as follows: • Lean Manufacturing Leader • Lean Coordinator
After an Action Work Out (AWO), it is very common to have additional people in the production lines. One of the initiatives adopted here is to take the person who best grasped Lean ideas and tools, they join the team. That way, the tacit knowledge created based on lived experience can be used to transmit it to new areas where the new AWO will be carried out.
Therefore, when selecting the internal team, it is very important to fulfill the following characteristics: • Lean requires a team that is committed and willing to learn.
• They must be willing to work and understand that real learning takes place in the workplace.
• The team must be multidisciplinary and their roles have to be clearly defined.
• Goals should be clear for each of the team members.

Training
The next step is to train the entire organization, introducing the initiative and the benefits and challenges that the organization will face by implementing it. After defining the vision, objectives, and goals, developing a training plan for all levels of the organization is fundamental in order to start speaking the same language. Initially, a training sequence is defined, starting with department leaders, then employees, coordinators, supervisors and operators, so that the support of this initiative comes from management. The other people who join the list of trained employees start creating what is called the "snowball effect", which means that once the idea is approved and adopted by the organization, the initiative gains momentum and the benefits start growing exponentially.

Reference: the authors
The training plan should not only have a sequence. A training plan that contains all the tools that have been defined to be implemented should be established.
The following are some of the advantages of Lean training at all organizational levels: • Ensure that the entire organization understands and speaks the same language.
• To obtain basic knowledge in the training room in order to execute more accurately in the workspace (Gemba).
• To explain the rules on which the methodology is based before implementation.

Tool implementation -Action Work Out
The next step of the methodology is the Action Work Out, which is going to the work area and applying the tools discussed in this paper. The steps to follow to perform the AWO are: -Familiarize yourself with the Process:

Becoming familiar with the Process.
It is very important that the team performing the AWO knows the process that will be carried out, for the team member to be able to identify the operations that add value and those that do not when observing operations and recording times. To do this it is necessary to read the procedures and instructions to see which operations are the ones that really need to be carried out, which are surplus, and which are not being carried out.

Identifying the 7 Wastages in the Workspace
Through process visualization and monitoring, the waste generated in diverse company processes will be identified.

Takt Time
The Takt

Time Taking
Time taking is vital, because this is where we can detect other wastes in which operators incur and that do not add value to the product, such as crane time, transportation, defects, etc. It is important to make around 10 samples when taking times which will be taken 10% by the process' engineer, 10% by the area supervisor, and the remaining 80% by the Lean team that was previously appointed; the purpose of this is that the process owners of such areas can become aware of their wastes and activities that do not add value to the operation, and that many times, due to the blindness of the workshop, are not able to be detected.
Once the times are taken, it is necessary to analyze them and see the differences between operators.

Identifying Operations
When taking operation times at workstations and performing the analysis, identify each of the operations that are carried out, these may be: • Manual operations that add value. These are the ones that transform the product and for which the customer is paying. It is important that the time spent on this type of activity is the highest share.
• Manual operations that do not add value. These are the operations that the operator performs manually but do not transform the product and therefore do not add value. It is necessary to try reducing the percentage of time that is lost performing these operations.
• Machine time. These are the machinery operating times, and it is imperative to identify and separate these activities so that the operator can perform other operations while the machine is working.
• Walking does not add value. In many organizations, it is very common to see an operator leaving his workstation in order to go pick up material, look for a measuring instrument, and so on. This is one of the most common types of waste and it is important to be able to pinpoint it.
Therefore, when taking time, it is important to be able to analyze and try to eliminate all activities that do not add value. This is because, if the Takt Time is not being fulfilled, eliminating these activities can help in producing within it.

Eliminating Non-Value Adding Activities.
Once non-value-adding activities have been established, they need to be eliminated from our process. If, before the AWO we were not complying with the Takt time, once we eliminate all those operations that do not add value, we will be able to produce within it.

Defining Standard Operations
Once the operations that do not add value have been eliminated, we must determine the sequence of operations that each operator has to follow, in order to produce units consistently within the Takt Time. When defining the sequence of operations, we have to remember that the operators are the ones who carry out the operation and that they are the ones who know it deeply.
There are many purposes of following a sequence of operations, among them we can mention: • Decreasing the number of malfunctioning parts.
• Facilitating the operation.
• To visually manage the operation.
• Improving and facilitating supervision.
• Make it easier to train other operators.
Once the AWO process has progressed, implementing tools should be carried out in the following way: Just because we are producing below Takt Time and following a sequence of operations to standardize the process, we should not stop working to improve our process continuously, we must remember that a lot of discipline and continuous work is required to be able to maintain the right level. In the world of Lean Manufacturing, a metaphor is made using a diet. It is hard for a person to lose weight and be in shape; but once they do, they have to keep exercising and eating healthy in order to stay Ingeniería Solidaria e-ISSN 2357-6014 / Vol. 17, no. 3 / september-december 2021 / Bogotá D.C., Colombia Universidad Cooperativa de Colombia at the desired level, and this is where it is very difficult to maintain. The same thing happens with Lean, in order to be able to work below Takt Time, we have to follow the standard operation routine (diet) while at the same time observing the operation to be able to detect any of the 7 wastes that appear in the process. That is why continuous improvement, better known by the Japanese as Kaizen, is of great importance in the organization to ensure success when implementing Lean.

Implementing Required Changes
"Mr. Ohno was passionate about TPS. He would say that he had to clean up and identify all the problems that existed in the workplace. He usually complained if he couldn't tell if there was a problem in a work area." [44], Fujio Cho, President, Toyota Motor Corporation.
All the areas of opportunity in a work area that have been found during an AWO must be addressed, and the necessary changes must be made in order to eliminate the problems' root cause. It is very common to see problems in organizations that are not aired, and are solved without letting the whole company know the reason or the cause of the problem. Normally they try to hide it, but in Toyota Production System (TPS) culture it is completely opposite, making it very important to visualize the problems so that they do not happen again.
So far, we have presented works from different authors that present methodologies to carry out an implementation, and we have also presented a proposal of a methodology that allows the implementation of Lean Manufacturing in the Colombian context. In addition, we have found a good compendium of experiences where, one or more Lean tools have been developed but now the question that arises is, how to determine the Lean strategy' development level in the companies, and how to know if the Lean Manufacturing methodology' execution process is being carried out correctly.

Results
Once the process previously mentioned in this work has been carried out, it is essential to be able to highlight the results obtained during the Lean tools' implementation.
A visual way to show these results is by using a tool called the Objectives Sheet.

Reference: the authors
The illustration above shows us all the parameters we should measure before starting a workout, and establishes a goal to achieve. At the end of the AWO, depending on the time frame, which can be a few hours or more than a week. Here we can see parameters such as: Cycle time, lead time, number of operators, inventory, travelling distance of a piece, liberated space, etc. Lean tools can be implemented independently, and this implementation can be done at different stages of the project. Additionally, there is a need to take into account cultural factors in each country, since they determine some organizational culture behaviors that can be obstacles to a successful Lean Manufacturing implementation.

DISCUSSION AND CONCLUSIONS
During this project, a methodology for Lean Manufacturing implementation was developed, based on pre-existing methodologies' literature and successful cases of Lean Manufacturing implementation in Colombia.
With the experience gathered, we can conclude that this methodology can help other organizations in the Lean Manufacturing implementation and above all, that the methodology outlined in this document is flexible rather than rigid, it will depend on the organization in which it is applied.

Future Research
During the research process, it became evident that there is a possibility of wasting the knowledge gained through experience. It is proposed as follow-up work to create a system in which knowledge management can be applied within the Lean Manufacturing implementation methodology for the Colombian context, so that expertise and insights gained by team members are not wasted, making them available for other members of the organization.
The results of the survey showed that the suppliers' development and the organizational culture modification are difficult aspects to deal with. Therefore, as a future research, we propose the characterization and adequate development for suppliers in the Lean Manufacturing implementation, starting from the country's logistic systems to achieve an adequate implementation of JIT in Colombia.