# Lean and Six Sigma Philosophies in Portuguese Laboratories

Andreia Craveiro, Vanda Lima, José Carlos Sá, Miguel Lopes, Gilberto Santos, José Dinis-Carvalho

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Andreia Craveiro, Vanda Lima, José Carlos Sá, Miguel Lopes, Gilberto Santos, et al. Lean and Six Sigma Philosophies in Portuguese Laboratories. 8th European Lean Educator Conference (ELEC), Nov 2022, Galway, Ireland. pp.82-92, 10.1007/978-3-031-25741-4_9. hal-04735673

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# Lean and Six Sigma philosophies in Portuguese laboratories

Andreia Craveiro¹, Vanda Lima¹, José Carlos Sá²,³, Miguel Lopes¹, Gilberto Santos⁴, José Dinis-Carvalho⁵

¹CIICESI, ESTG, Politécnico do Porto, Portugal

8170003@estg.ipp.pt, vlima@estg.ipp.pt, aml@estg.ipp.pt

²School of Engineering, ISEP, Polytechnic of Porto, Porto, Portugal

cvs@isep.ipp.pt

³Institute of Science and Innovation in Mechanical and Industrial Engineering
(INEGI), Porto, Portugal

⁴Design School, Polytechnic Institute Cavado Ave, Barcelos, Portugal

gsantos@ipca.pt

5Production and Systems Department - University of Minho, Guimarães, Portugal

dinis@dps.uminho.pt

**Abstract.** Increased consumer demand as well as increased competition, has led organizations to need continuous improvement. The Lean and Six Sigma philosophies, widely applied in industry, have shown important results in terms of process improvement, which has attracted the attention of many organisations, including services.

This research aims to characterize the degree of knowledge and implementation of Lean and/or Six Sigma philosophies in Portuguese laboratories. Data collection was carried out using a questionnaire applied to a population of laboratories, including clinical, testing and calibration laboratories, as well as accredited and non-accredited laboratories. The results show that most laboratories are not familiar with Lean and/or Six Sigma philosophies. Furthermore, it is noted that the laboratories that have implemented these philosophies are those with the highest number of employees and turnover.

**Keywords:** Lean, Six Sigma, Lean Six Sigma, Portuguese Laboratories.

## 1 Introduction

With an increasingly globalized market, companies see as imperative the need to implement a culture of continuous improvement in order to cope with the constant volatility of the market. In this context, Lean and Six Sigma philosophies, widely applied in industry, have been adopted by services, given the positive results observed in organizations in terms of process improvement [1-4].

The laboratory sector has also felt this competitive pressure from the market, and it is urgent to maintain processes with a high level of flexibility and value creation [5].
More and more laboratories are faced with superior challenges associated with increased workload and cost reduction, and therefore there is a need to increase efficiency and quality levels [6].

This research aims to characterize the degree of knowledge and implementation of Lean and/or Six Sigma philosophies in Portuguese laboratories.

To accomplish this goal, a quantitative research methodology was used, with primary data collection through an online questionnaire addressed to Portuguese laboratories.

# 2 Literature Review

## 2.1 Lean thinking

The foundations for Lean thinking can be attributed to Henry Ford (1913) for his implementation of a process flow that translated into low-cost mass production associated with employee involvement [7]. However, it was only in the 1950s, after the Second World War, that the Toyota Production System emerged in Japan, developed by Taiichi Ohno, on which the current principles associated with Lean thinking are based. The Toyota Production System focuses on waste reduction, thus working with the cost variable and leading to improved production efficiency and value creation for the customer. The Lean concept appeared only in the late 80's put forward by researchers from MIT - Massachusetts Institute of Technology. The worldwide divulgation arose from Womack, Jones & Roos in the first edition of in 1991 of their book "The machine that changed the world" [3], [4], [8], [9].

"Lean is the term used to describe a management philosophy and set of principles for the continuous improvement of any production process, focusing on eliminating waste and creating a better product from the customer's point of view" [7].

Lean Thinking is based on five fundamental principles [3], [4], [7], [8]:

1. Identify value - identify what value means from the customer's point of view in order to create value that is perceived by the customer as such;

2. Map the value chain - identify the sequence of actions and processes that enable value to be created for the customer;

3. Create a flow - promote a continuous flow of value-generating activities, ensuring that everything that does not add value to the process is eliminated

4. Establish Pull - producing only what is needed, when it is needed and in the quantity needed; production should be "pulled" by the customer, eliminating stocks

5. Seek continuous improvement - continuously seek improvement (kaizen) in the processes, in order to reduce costs, deadlines, errors, spaces and create new forms of value.

The goal of Lean thinking is the transformation of waste into value from the customer's perspective, where waste is something that does not add value to the final product or service and for which the customer is not willing to pay [3], [9], [10].

For the implementation of the Lean philosophy several tools can be used [3], [4], [11-15], among which we highlight: Value Stream Mapping, 5S, Visual management,
Standardized work, Single Minute Exchange of Dies (SMED), Poka-Yoke, One piece flow production, Production balancing, Pull system, Kanban, Heijunka, Mizusumashi, Jidoka, Spaghetti diagram, Gemba (shop floor), Total productive maintenance (TPM), Organization of people in work cells, A3 Problem Solving and Kaizen (continuous improvement).

## 2.2 Six Sigma

The Six Sigma philosophy emerged in the 1980s at Motorola, with the objective of reducing the variation associated with the processes. Based on the work developed in Japanese companies, the creation and implementation of the first Six Sigma improvement program was promoted. Motorola achieved a significant increase in profits by reducing costs and process variation. Later, in the 1990s, General Electric, also reported impressive gains and savings after implementing several Six Sigma projects. The success of these companies led to increased global interest in this philosophy [1], [16].

Six Sigma is defined by General Electric as a "highly disciplined process that leads to the development and delivery of near-perfect products and services". The main tenet of Six Sigma is to be able to measure how many defects exist in a process, systematically figure out how to eliminate them, and get as close to zero defects as possible. To achieve Six Sigma Quality a process should produce no more than 3.4 defects per one million opportunities [16].

Six Sigma relates the variation in a process to customer requirements and a defect is any value that does not meet the customer's specifications [17]. According to the literature, the results obtained with the application of this philosophy in terms of defect reduction and process improvements are well known [18].

The Six Sigma philosophy is supported by a methodology, which is based on five phases: DMAIC - an acronym for Define, Measure, Analyze, Improve and Control - and focuses on existing processes to improve their performance [1], [17], [19].

In the process of implementing the Six Sigma philosophy, various quality techniques and tools are used, namely [12]–[14], [20]–[25]: Process capability analysis, Critical to Quality tree (CtQ), Brainstorming, Deployment diagram, Gantt diagram, Failure Mode and Effects Analysis (FMEA), Six Sigma metrics, Project charter, House of Quality, Sigma-metrics method decision chart, Suppliers, Input, Process, Output, Customers (SIPOC), Statistical Process Control (SPC), and Measurement Systems Analysis (MSA).

## 3 Method

A quantitative research methodology was used, based on a survey research strategy, and using an original, pre-tested, validated online questionnaire as a data collection instrument [26]. The online questionnaire was disseminated to Portuguese laboratories. Data collection was carried out through the Google Forms platform during October and November 2019.
The population consisted of 695 laboratories, including accredited/certified and non-accredited/certified clinical, testing, and calibration laboratories. A response rate of 15% was achieved, and the final sample comprised 106 laboratories. According to [26] in survey methodology studies the response rate tends to be around 10 to 20%.

The questionnaire design considered several aspects to ensure the consistency of responses, such as: the characteristics of the respondents, the structure of the questionnaire, the type, scales and number of questions, among others [26]. In order to avoid invalid questionnaires, facilitate data analysis and increase the objectivity of the answers, we chose to formulate mostly closed-ended and mandatory questions [27], using five-point Likert-type scales [28].

In the following sections descriptive and inferential analyses of the data are presented.

## 3.1 Population and sample

In this section, the population and the sample are described.

Of the 695 laboratories included in the population, 9 (1%) are accredited clinical laboratories, 343 (50%) are accredited testing laboratories, 58 (8%) are accredited calibration laboratories, 120 (17%) are certified laboratories, and 165 (24%) are not accredited or certified laboratories (see Figure 1).

Regarding the sample, 1 (1%) is an accredited clinical laboratory, 67 (63%) are accredited testing laboratories, 8 (8%) are accredited calibration laboratories, 15 (14%) are certified laboratories, and 15 (14%) are not accredited or certified laboratories (see Figure 1). As can be seen, the sample represents the population in an appropriate way.

<figure><img src="image_3.png" /><figcaption>Fig. 1. Population and sample by laboratory type</figcaption></figure>

Regarding the size of the laboratories (Table 1), there's a higher representation of laboratories with less than 30 employees (77%). Laboratories with 31 to 50 employees and with 51 to 100 employees represent (18%) of the sample (9% each category). Only 5% (5) are large-sized laboratories (more than 100 employees).
<table><caption>Table 1. Laboratories by size</caption><thead><tr><th>Number of employees</th><th>N</th><th>%</th></tr></thead><tbody><tr><td>101 to 250</td><td>5</td><td>5%</td></tr><tr><td>51 to 100</td><td>10</td><td>9%</td></tr><tr><td>31 to 50</td><td>10</td><td>9%</td></tr><tr><td>11 to 30</td><td>26</td><td>25%</td></tr><tr><td>1 to 10</td><td>55</td><td>52%</td></tr><tr><td>Total</td><td>106</td><td>100%</td></tr></tbody></table>

According to Figure 2, the large majority of the laboratories in the sample (76%) have a turnover of up to €1 million. Only 2% of the laboratories have a turnover of more than €10 million.

<figure><img src="image_4.png" /><figcaption>Fig. 2. Laboratories by turnover</figcaption></figure>

The characterization of the sample allows us to conclude that it adequately represents the Portuguese laboratory sector.

# 4 Results

In this section the results obtained through the questionnaire are reported.

The questionnaire allowed us to understand if the laboratories were aware of and had applied the Lean and Six Sigma philosophies (see Figure 3). Regarding the level of knowledge of Lean Thinking, 52% (55) of the laboratories were unaware of this philosophy. Similarly, it can also be seen that most laboratories are not familiar with Six Sigma (56%; 59 laboratories).
<figure><img src="image_5.png" /><figcaption>**Fig. 3.** Level of knowledge of the Lean and Six Sigma philosophies</figcaption></figure>

Taking into consideration the types of laboratories, it is the clinical and testing laboratories that have a higher level of unawareness of the two philosophies. On the other hand, calibration laboratories have the highest levels of knowledge.

The questionnaire allowed us to understand the reasons for not implementing Lean and/or Six Sigma philosophies. The main reasons pointed out were: (1) satisfaction with the management and quality systems already implemented in the laboratories; (2) lack of human resources; and (3) financial unavailability.

<figure><img src="image_6.png" /><figcaption>**Fig. 4.** Level of application of the Lean and/or Six Sigma philosophies</figcaption></figure>

Of the 106 laboratories in the sample, only 16 have implemented at least one of the philosophies. Figure 4 shows that 37% (6) have implemented Lean Thinking, 19% (3) Six Sigma, and 44% (7) both philosophies (Lean Six Sigma).

The analysis by type of laboratory, allows us to see that the vast majority of laboratories 69% (11) are testing laboratories. It is also verified that 94% (15) of the laboratories that have at least one of the philosophies implemented are accredited and/or certified laboratories.

In order to understand if the implementation of Lean and Six Sigma philosophies are associated with the size and the turnover of the laboratories, we proceeded to a cross tabulation analysis.
<table><caption>**Table 2.** Cross tabulation: Lean and Six Sigma implementation and laboratory size</caption><thead><tr><th rowspan="2"></th><th rowspan="2"></th><th colspan="5">Number of employees</th></tr><tr><th>1 to 10</th><th>11 to 30</th><th>31 to 50</th><th>51 to 100</th><th>101 to 250</th></tr></thead><tbody><tr><td rowspan="2">Lean Thinking</td><td>No implementation</td><td>N.°<br/>%</td><td>54<br/>58.1%</td><td>22<br/>23.7%</td><td>9<br/>9.7%</td><td>6<br/>6.5%</td><td>2<br/>2.2%</td></tr><tr><td>Implementation</td><td>N.°<br/>%</td><td>1<br/>7.7%</td><td>5<br/>38.5%</td><td>1<br/>7.7%</td><td>3<br/>23.1%</td><td>3<br/>23.1%</td></tr><tr><td rowspan="2">Six Sigma</td><td>No implementation</td><td>N.°<br/>%</td><td>55<br/>57.3%</td><td>23<br/>24.0%</td><td>8<br/>8.3%</td><td>7<br/>7.3%</td><td>3<br/>3.1%</td></tr><tr><td>Implementation</td><td>N.°<br/>%</td><td>0<br/>0.0%</td><td>4<br/>40.0%</td><td>2<br/>20.0%</td><td>2<br/>20.0%</td><td>2<br/>20.0%</td></tr></tbody></table>

Table 2 shows that the larger laboratories tend to be the ones that have implemented Lean and Six Sigma philosophies. This conclusion is corroborated by the chi-square tests and their symmetry measures, which reveal that there is a moderate and statistically significant association between the variables analyzed (see Table 3).

<table><caption>**Table 3.** Chi-Square tests and symmetric measures: Lean and Six Sigma implementation and laboratory size</caption><thead><tr><th>Variables</th><th>Tests and measures</th><th>Value</th><th>Significance</th></tr></thead><tbody><tr><td>Lean Thinking<br/>*</td><td>Pearson Chi-Square</td><td>20.909<sup>a</sup></td><td>&lt;0.002<sup>b</sup></td></tr><tr><td rowspan="2">Number of employees</td><td>Cramer's V</td><td>0.444</td><td>&lt;0.002<sup>b</sup></td></tr><tr><td>Contingency Coefficient</td><td>0.406</td><td>&lt;0.002<sup>b</sup></td></tr><tr><td>Six Sigma<br/>*</td><td>Pearson Chi-Square</td><td>15.141<sup>a</sup></td><td>&lt;0.13<sup>b</sup></td></tr><tr><td rowspan="2">Number of employees</td><td>Cramer's V</td><td>0.378</td><td>&lt;0.013<sup>b</sup></td></tr><tr><td>Contingency Coefficient</td><td>0.354</td><td>&lt;0.013<sup>b</sup></td></tr></tbody></table>

Concerning the association between the implementation of Lean and Six Sigma philosophies and the turnover of the laboratories, it is also found that the larger ones tend to implement more these philosophies, especially regarding Lean Thinking (see Table 4).

<table><caption>**Table 4.** Cross tabulation: Lean and Six Sigma implementation and laboratory turnover</caption><thead><tr><th rowspan="2"></th><th rowspan="2"></th><th colspan="5">Turnover</th></tr><tr><th>&lt;1 M€</th><th>&gt;1 to &lt;2 M€</th><th>&gt;2 to &lt;10 M€</th><th>&gt;10 to &lt;50 M€</th><th>50 M€</th></tr></thead><tbody><tr><td rowspan="2">Lean Thinking</td><td>No implementation</td><td>N.°</td><td>49</td><td>5</td><td>4</td><td>0</td><td>0</td></tr><tr><td></td><td>%</td><td>84.5%</td><td>8.6%</td><td>6.9%</td><td>0.0%</td><td>0.0%</td></tr></tbody></table>

<footnote><sup>a</sup> 5 cells (50.0%) have expected count less than 5.</footnote>

<footnote><sup>b</sup> Monte Carlo significance: Based on 10000 sampled tables</footnote>
<table><thead><tr><th colspan="7">Turnover</th></tr><tr><th></th><th></th><th colspan="2">&lt;1 M€</th><th>&gt;1 to &lt;2 M€</th><th>&gt;2 to &lt;10 M€</th><th>&gt;10 to &lt;50 M€</th><th>50 M€</th></tr></thead><tbody><tr><td></td><td>Implementation</td><td>N.°</td><td>3</td><td>2</td><td>3</td><td>1</td><td>1</td></tr><tr><td></td><td></td><td>%</td><td>30.0%</td><td>20.0%</td><td>30.0%</td><td>10.0%</td><td>10.0%</td></tr><tr><td rowspan="2">Six Sigma</td><td>No implementation</td><td>N.°</td><td>50</td><td>5</td><td>4</td><td>1</td><td>1</td></tr><tr><td></td><td>%</td><td>82.0%</td><td>8.2%</td><td>6.6%</td><td>1.6%</td><td>1.6%</td></tr><tr><td></td><td>Implementation</td><td>N.°</td><td>2</td><td>2</td><td>3</td><td>0</td><td>0</td></tr><tr><td></td><td></td><td>%</td><td>28.6%</td><td>28.6%</td><td>42.9%</td><td>0.0%</td><td>0.0%</td></tr></tbody></table>

Table 5 shows that there is a moderate and statistically significant association between the implementation of Lean and Six Sigma philosophies and turnover.

<table><caption>**Table 5.** Chi-Square tests and symmetric measures: Lean and Six Sigma implementation and laboratory turnover</caption><thead><tr><th>Variables</th><th>Tests and measures</th><th>Value</th><th>Significance</th></tr></thead><tbody><tr><td>Lean Thinking<br/>*</td><td>Pearson Chi-Square</td><td>20.406<sup>a</sup></td><td>&lt;0.001<sup>b</sup></td></tr><tr><td rowspan="2">Turnover</td><td>Cramer's V</td><td>0.548</td><td>&lt;0.001<sup>b</sup></td></tr><tr><td>Contingency Coefficient</td><td>0.480</td><td>&lt;0.001<sup>b</sup></td></tr><tr><td>Six Sigma<br/>*</td><td>Pearson Chi-Square</td><td>13.141<sup>a</sup></td><td>&lt;0.019<sup>b</sup></td></tr><tr><td rowspan="2">Turnover</td><td>Cramer's V</td><td>0.440</td><td>&lt;0.019<sup>b</sup></td></tr><tr><td>Contingency Coefficient</td><td>0.402</td><td>&lt;0.019<sup>b</sup></td></tr></tbody></table>

## 5 Conclusion

Like what happens in the corporate environment, where these philosophies were primarily developed in large industrial companies, this study also found that in the laboratory environment, it was the laboratories with the largest size and turnover that implemented these philosophies. Of the 16 laboratories that implemented Lean e/or Six Sigma, only one did not belong to a larger corporate structure, and 76% had a turnover greater than 1 million Euros, quite different from the total sample where 76% of the laboratories had a turnover less than 1 million Euros. It should also be realized that, in the case of the number of employees, the laboratories that have implemented at least one of the philosophies have a larger number of employees, on average, almost double those that have not.

Since the Portuguese business environment is essentially characterized by micro, small, and medium-sized companies, which, despite playing an important role in the development of the country's economy, sometimes face some limitations inherent to

<footnote><sup>a</sup>6 cells (60.0%) have expected count less than 5.</footnote>

<footnote><sup>b</sup>Monte Carlo significance: Based on 10000 sampled tables</footnote>
the lack of resources, a more traditional management, and a lower degree of develop-
ment, which may affect the need for initial investment in training, time, and human
resources inherent to the implementation of Lean and/or Six Sigma philosophies.

From the data analysis it was found that the biggest limitations to the implementation
of both philosophies were the lack of human resources, financial unavailability, and
satisfaction with existing management and quality systems, which is in line with the
already known characteristics of the Portuguese business environment. Also, the fact
that only 14% of the laboratories in the sample are not accredited and/or certified may
explain the satisfaction of most laboratories with the management and quality systems
already implemented, and not moving towards Lean and/or Six Sigma philosophies.

This study contributes to increase the knowledge of Lean and Six Sigma
philosophies at laboratory level. Research in Portugal has been focused on the
application of Lean and Six Sigma philosophies in companies. The studies in
laboratories are limited and usually address case studies. Therefore, this study
contributes to an exhaustive diagnosis of the situation in Portugal, allowing the
identification of opportunities for improvement in the sector.

This study also contributed to the construction of an original questionnaire that can
be directly applied or adapted in future work within the scope of Lean and Six Sigma
philosophies.

The main limitation of the study is related to the sample size. Although the response
rate is acceptable [26], a larger sample size would have allowed for more robust
statistical analyses.

In the future, it is suggested to use the questionnaire developed in this study in a
larger sample of laboratories. It is also suggested that interviews be carried out in
Portuguese laboratories with implemented Lean and/or Six Sigma philosophies, in
order to understand the implementation approach, advantages and disadvantages,
benefits and difficulties.

Research funding

The work of the author Vanda Lima is supported by national funds, through the
FCT—Portuguese Foundation for Science and Technology under the project
UIDB/04728/2020.

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