Her mission: create the optimal assembly line

The distribution of tasks over work stations within the manufacturing industry around the globe is far from optimal. With ergonomics nowadays widely integrated in the production environments, it is time to include it in the balancing process. Is it possible for the seemingly contradicting objectives of ergonomics and productivity, to be combined? At the Smart Factory Lab at SCANIA, we find the 25 year old master student Janneke Vollebregt from The Netherlands. She is investigating this in her thesis work “Including Ergonomics in the Assembly Line Balancing Process”.

Janneke Vollebregt next to the pedal-car assembly where her tool will be tested

Janneke has only been to Sweden for a couple months when we contact her to find out more about her thesis. Turns out SCANIA has always been close to Janneke’s heart. During her childhood she spent hours listening to her father talking about his work at SCANIA, so when she got the opportunity to do her thesis work at SCANIA’s Smart Factory Lab in Södertälje, Sweden, it was an easy choice.

- I was very happy when I heard back from Smart Factory Lab about doing my thesis project here. It is an innovative and fun environment to be in. Before I go back home I hope to have tested my tool in our pedal-car assembly, says Janneke.

In her thesis, Janneke is looking at including productivity and ergonomics, simultaneously, in the manual line balancing process. She is also developing a tool that assess the two perspectives and propose the optimal set-up. Both methods must include practical aspects, such as a mixed-model assembly line. No wonder Janneke’s thesis has already gained attention from both the academia and automotive industry.

Efficiency vs ergonomics?

When planning production, the assembly line balancing process is essential. It identifies the optimal flow – from start to finish, but what often overlooked at this stage is ergonomics. High productivity currently comes first and before Janneke, no one has tried consider both factors at the same time at Scania.

- Available programs for line balancing do not weigh in the ergonomic perspective, it identifies the most efficient set-up, considering time and cost. The ergonomic perspective is currently analyzed by observation in real life. A task that takes an ergonomist about four hours per operator. I suggest using simulated ergonomics assessments programs to add this perspective to the balancing process in a time-efficient manner, says Janneke.

Screen shot from IPS/IMMA simulation in which Janneke assess tasks by using manikins.

From manual input to automized output

The thesis is divided into two steps. In the first, Janneke and a team of developers establish a connection between the existing ergonomic assessment tool (IPS/IMMA) and the balancing tool (AviX).

- In this manual optimization step I am working together with software developers. The connection has to be able to execute the ergonomic assessments and link the results to the tasks. I am collaborating with two larger research projects from the University of Skövde, the Synergy Virtual Ergonomics and MOSIM, says Janneke.

In the next step, Janneke develops the automated balancing process tool. The user is able to put in data from the AviX-IPS/IMMA connection considering task times and ergonomic risk scores. After which, the tool will suggest ways to optimize the process.

- Not only will this tool improve the balancing process, it will also demonstrate how simulation, optimization, and digitalization methods and technologies can contribute to an efficient consideration of ergonomics. This automated part of my thesis is done in collaboration with the research profile VF-KDO, says Janneke.

Maximum productivity, minimal work related injuries

Traditionally, productivity has been the driving force, but now, when the interest of ergonomics is growing, it is not sustainable to only consider the productivity parameter. To eliminate work related injuries many factors needs to be considered, but there is no tool or software that incorporate the ergonomic risks at such an early stage as balancing. Janneke’s tool will change this. To make sure the tool will fulfill its intended function, it will be tested and compared with traditional procedure at the pedal-car assembly station.

- The pedal-car assembly at the Smart Factory Lab is a station where new methods can be tested. During my work, data from the pedal-car assembly; measurements, angles, heights, tasks etc. will be put into the tool. I am quite excited about the test. I hope it will be successful and that, down the road, it will contribute to a better assembly line balancing process at Scania, concludes Janneke.

If successful, Janneke’s tool will revolutionize the way manufacturing companies will look at ergonomics and how this, together with the productivity, contributes to creating the optimal assembly line.


VF-KDO is financed by: