Propelled more than 50 years ago by Toyota, Lean is today widely known and spread in many companies. It can even be said that companies that use Lean are more successful than others.
Indeed, several studies show that companies applying Lean have a higher performance than comparable companies in the same sector.
Lean has the reputation of degrading working conditions. Yet by associating a participative approach to continuous improvement, the Lean approach is supposed to enhance the place of operators.
This valorization of the operators leads to focus on ergonomic issues and to position the Lean approach as an opportunity to prevent health and safety risks in the company, provided of course that the approach is properly appropriated.
In recent years, ergonomics has therefore become an ally in a Lean approach. Indeed, it is no longer a question of confronting them but rather of finding the articulations between the two approaches. Indeed, it is no longer a question of confronting them but rather of finding the articulations between the two approaches. But what is ergonomics? Why is there an opposition between these two concepts? What are the impacts on your Lean approach? What are the impacts on your Lean approach?
This article will explore these questions and shed light on the importance of the duality of these two approaches in your search for performance.
What is ergonomics?
Ergonomics is the scientific study of the relationship between people and their work environment; it is also the application of this knowledge to the design of systems “that can be used with maximum comfort, safety and efficiency by the greatest number of people”.
Good ergonomics adapts the work to the person rather than forcing him or her to adapt to the work. In an ergonomic workplace, tasks and tools are designed to adapt to individual abilities and limitations so that people can do their jobs without injury.
Ergonomics has emerged as a hot topic because it shows the link between certain types of injuries and the way people do their jobs. We now realize that the human body cannot remain in uncomfortable or unnatural positions for long periods of time without paying the price.
Musculoskeletal disorders (MSDs) are probably the most common physical problem resulting from poor ergonomics. MSDs are pathologies with multifactorial causes and develop over long periods of time.
They include a large number of chronic, sometimes very disabling diseases that affect nerves, tendons, tendon sheaths and muscles, particularly in the arms, hands and wrists.
MSDs are sometimes called “repetitive strain syndrome” because repetitive strain is a common cause of this problem.
Other causes include violent exertion, vibration and uncomfortable positions or movements. The more you expose your body to any of these situations, the more likely you are to develop a painful problem.
The following is a non-exhaustive list of factors that can lead to the development of ergonomic risks :
- Individual factors : age, gender, poor health status
- Biomechanical factors: Repetitiveness, static working posture, use of vibrating tools, stress
- Psychosocial factors: Intensity of work time, conflicts, stress, job satisfaction
- Organisational factors: work organisation, lack of breaks, tense flow, exposure time, etc
Some of these pathologies are recognized as occupational diseases and may therefore be subject to compensation (Table 57 Decree of November 2, 1972, Last updated : Decree of May 5, 2017).
Musculoskeletal disorders (MSDs) alone account for 10 million days of work stoppage, according to Health Insurance figures, and 930 million euros in costs covered by company contributions for the general scheme assets.
In addition to public bodies, companies themselves are directly impacted in their performance by the MSD phenomenon. Indeed, the financial impact is immediate as soon as a qualified employee can no longer carry out the tasks assigned to him/her.
In the current context of globalization, quality requirements and strong competitiveness, manufacturers looking for ways to increase productivity and performance are opting for a Lean approach.
This approach will have to be accompanied by considerations in favor of health and safety at work. The results will depend on how the Lean tools will be articulated with an analysis of your company’s ergonomics.
Ergonomics and Lean
Numerous studies have noted the negative effects of Lean. In 2006, the Centre d’Etudes de l’Emploi (Center for Employment Studies) pointed out that companies that have implemented a Lean approach would generate more stress than other companies, just as employees would feel more damage to their health.
This can be explained by the use of Lean, which is far removed from its founding philosophy, as it is seen as a deployment of the approach that is based on a distorted representation of performance and the exclusion of employees in the field in the approach.
By distorted representation of the approach, I mean that the company does not take into account the indirect costs related to the social dimensions of work and the company.
Lean is seen as an opportunity because of the importance it gives to the operators, to the field, and to the improvement supported by the participation of the operators.
There are already known Lean tools for different issues, for example the analysis of flow problems, non-quality, understanding the organization (Spaghetti diagram, PDCA, VSM,5S …).
However, for the analysis of the workstation, there are specific tools to help detect the lack of ergonomics:
- RULA (Rapid Upper Limb Assessment): allows the analysis of joint angles in work situations
- In-depth analysis of the physical workload: on the INRS site
- Identification grid of the physical load (ED 6161 Feb 2014 – INRS): on the INRS website
Following the screening, actions must be carried out based on the following axes :
- Organization: improvement of flows, work processes and management
- The technic: improvement of processes, introduction of IoT
- Human resources: focus on training, federation of teams
The link between the Lean approach and ergonomics no longer needs to be demonstrated, as it is explained in the report by the Centre d’Etude de l’Emploi on the working conditions and occupational health of European Union employees (research carried out by DARES, Ministry of Labor, 2006).
Wanting to oppose a Lean approach to ergonomics is a sterile debate that only delays the smooth running of the approach and the achievement of the targeted performance.
The Lean approach is being transformed and organized around the search for solutions that combine the enhancement of human factors and professional performance, which is why it is best to understand that such an approach can also be an opportunity for prevention.
At this level, it is no longer a question of being for or against the Lean approach but of participating in the elaboration of solutions that take into account the human factor, in a logic of optimization of working conditions and on the basis of a participative approach and efficiency at work.