Productivity requirements in high volume manufacturing industry necessitate
the widespread use of machine-based assembly stations. Although high
production volumes can be achieved by a small number of workers
(operators) the resulting fatigue on these operators is often overlooked in the
design of the assembly station. Fatigue mitigation is then required via job
rotation on the shop floor but this is both unsatisfactory and a partial solution
The aims of this thesis are:
~ to develop an approach to the design of operator-centric assembly
~ to evaluate this approach in real life case study applications
~ to produce an evaluative tool which embodies "best practice" for use by
designers enabling them to aim to avoid or mitigate musculoskeletal
disorder problems for operators.
The thesis reviews current approaches to the design of ergonomic- and
process-driven assembly stations using literature available in the public
domain which includes guidelines, regulations, and legislative requirements
for health and safety.
Also reported is work undertaken by the author, at H R Adcock Ltd, on two
assembly stations which have been comprehensively re-designed in response
to unacceptable health risks for the workforce, poor quality products and a low
production rate. The original design and operation of the two stations will be
analysed along with the techniques used for their improvement.
The core of this thesis is to demonstrate a 'best practice' design approach to
the re-design and to evaluate the outcome. It became clear during the
compilation of this thesis that if it were possible to incorporate some simple
checking procedures which would identify all potential hazards and evaluate
risks early in the design process then this would eliminate or reduce the need
for costly downstream design changes.
The system developed is RIMAN - an acronym for Risk MANagement
RIMAN incorporates the following:
~ Development of design criteria
~ Co-operation between disciplines to facilitate the development of the
~ Risk identification
~ Evaluation of identified risks and assessment of how to eliminate or
reduce them to an achievable level
~ Utilisation of RIMAN as a recording/auditing tool and as a technical
folder which would outline the regulations and standards used in the
design criteria and specify the risk levels identified by risk evaluation.
RIMAN was successfully evaluated, retrospectively, against the assembly
station case study already mentioned. It demonstrated how particular risks
were identified and dealt with early in the design process. It is proposed that
further work is undertaken on a RIMAN version 2 and that the tool be actively
incorporated into the working practices of H. R. Adcock Ltd., or any company,
on a live design project.
A Masters Thesis. Submitted in partial fulfilment of the requirements for the award of Master of Philosophy of Loughborough University.