EAWS

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The need to identify the degree of exposition to biomechanical load has led at the beginning of the new millennium to the development of specific ergonomic risk screening tools; aim of these tools is to analyse the risk factors that may lead to overload the operator and eventually to occupational diseases. As always, the final goal is  the redesign of the work system so that the any risk can be minimized and the performance eased.

The basis of every ergonomic risk screening tool is to estimate the correlation between the task ergonomic characteristics (force, frequency, postures, etc.) and the probability to cause an occupational disease. The main difficulty is to establish how the different factors interact and lead to work related troubles or diseases.

Certainly the best approach is the prevention of the risk in the design phase of the work system (preventive ergonomics); if the product and/or the process is already defined, changes may be too costly and less efficient (corrective ergonomics).

For a quantitative ergonomic risk evaluation of a specific working sequence, generally two evaluation levels are used:

First level tools: risk screening tools which require a quick checklist.

Second level tools: risk evaluation tools which require a detailed analysis with index calculations. They are applied where a possible risk has been already detected by a 1st level system and the “risk generator” is not yet well identified.

The aim of First level tools is to get a very quick mapping of the different risk areas and to concentrate all the efforts on a rapid redesign. With the Second level tools specific loads are analyzed in detail, since the first level corresponding tool was insufficient to identify the origin of the risk.

Though the EAWS is presented as First level tool, it is quite analytical and it always identify the origin of the risk.

In the following table the risk areas, the correlated standards and the most common ergonomic tools are summarized.

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Project development history

EAWS is originally an extension of the Automotive Assembly Worksheet (AAWS) developed by the IAD (Institut of Ergonomics at the Darmstadt University of Technology) on the basis of the “New Production Worksheet”, initiated 1997 by General Motors Europe (GME), and the “DesignCheck”, realized at the same time at Porsche. The development of the EAWS was carried out between 2006 and 2008, by occupational health, biomechanical and industrial engineering international experts from all over the world, coordinated by the IMD (International MTM Directorate).

The field test was run in multinational companies that allowed the team to analyze relevant processes that represented different production contests. In this way all the necessary tests were performed before the last release of the tool (Field Application Group).

In addition, software companies were involved during EAWS development in order to implement and develop specific software solutions based on EAWS structure (Engineering Application Group).

IMD and national MTM Associations, together with the experts that worked with the team, gave all the tests results to the reference teams that represent the EAWS users main process partners (Reference Groups). The general project organization during the development phase was the following:

Field Application Group

ITALY AND FRANCE

MTM Italia

• I. Lavatelli, International MTM Instructor (PwC)
• A. Tassinari, International MTM Instructor (PwC)
• C. Rubano, MTM Instructor (PwC)

FIAT auto, Mirafiori Torino Plant

• Ergonomy: S. Torrisi and S. Spada
• Planning & Control: L. Galante, R. Bonetti, M. Capoccia, M. Vitello

BOSCH Diesel Technologies and Breaking Systems (BA)

• Industrial Engineering : M. Mancino and V. Nicassio

WE: Whirlpool Europe (Home Appliances), Amiens plant, France

• R. Delrue

IVECO: commercial vehicles, Suzzara plant

• H&S: S. Cencetti,
• Ergonomy: F. Leoni
• Work Analysis: G. Condò?

GERMANY (IAD)

• R. Bruder
• K. Schaub 

Volkswagen: automotive (IAD)

• Industrial Engineering: J. Nanasi
• Ergonomy: B. Toledo Munoz, R. Filus 

Bosch: (IAD)

• Bosch components
• Bosch- Siemens home appliances
• Bosch Rexroth tools

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EAWS modes of use and basic structure

The EAWS system can be used in two different modes, which differ in scope and calculation procedure:

“Instantaneous” risk mappingpreliminary workstation re-design for a specific worker

For a quick ergonomic risk assessment on an observed specific worker performing the work task on the shop-floor (observational method)                         

Paper & pencil tool à two double-sided A4 sheets with interpolation

Analysis refers to observed work task and operator (deviation risk from planned method)              

Risk factors estimated by users (forces, durations, frequencies, etc…)                         

Quick workstation re-design

ergonomic risk assessment of the workstation on a generic worker performing the standard work task (MTM method)                         

Software tool: IVGA (Excel based)                         

Useful to assess the ergonomic impact of method improvement opportunities

ERGO-MTM workstation design

For a preventive and analytic ergonomic risk assessment on an anthropometric group of operators performing a work task (MTM method)

Software tool: TiCon – MTMergonomics®

Inputs needed:

MTM task analysis

Production plan for frequencies calculation

MTM codes ergonomic characterization (geometries, forces, weights, etc…) 

Production flow macro-geometries (heights) and product positions (high, low, etc…)