Common Automation Process System
and Ergonomics Research study
-CASPER
Project AFM212Br, completed
by INBIS, Loughborough University
(Ergonomics and Safety Research
Institute),and University of Salford
September 2003 – April 2004
Patrick Williams – MSc, MRAeS, MCMI–
Casper Project Manager, INBIS
CASPER
Introduction
The Casper programme was defined between INBIS and
Marks and Spencer following the success of the ASAP AFM
173 R&D programme, and concerns with ergonomic issues in
the food assembly sector.
Developed in to AFM212Br with DEFRA.
Objectives
1.
To consider whether more common automation techniques
can be applied across a wider area of the food
production/assembly sector
2.
Complete a limited Evaluation of the ergonomics issues in
food production/assembly operations and consider the
implication for the sector
CASPER
Supply chain
Marks and Spencer identified the following organisations where
maximum benefits may be possible :
•
Gunstones – Bakery and filled roll production
•
RHM – Avana Cake decoration
•
Tulip – Meat slicing
•
Uniq PFF - Salmon processing
Deliverables
•
Individual company assessment reports for use within the
companies.
•
Report on ergonomics issues in the sector, and common
automation opportunities, and a proposal for progressing these.
CASPER
Analysis
Two distinct analysis processes :
Automation
• Evaluation of current processes,
• Assessment automation techniques currently available,
• Assessment against new technology,
• Consideration of operational scope of robotics/mechatronics,
• Process assessment using ‘Lean Thinking’ 5S methods
(Automotive/Aerospace industry), for more effective and efficient
operations.
CASPER
Ergonomics –
• Observation/video of worker motions and evaluation using
Rapid Upper Limb Assessment (RULA) (McAtamney and
Corlett, 1992 and 1993) techniques, for physical strain and
discomfort, and impact due to repetitive motion.
• Reach, and height dimensional assessment against ergonomic
standards
• Interviews providing supporting evidence on physical comfort,
and non physical aspects of repetitive work,
• Assessment of worker and management interaction in the
design of processes.
• H&S perspective and formal records for Work Related Upper
Limb Disorders (WRULD’s).
CASPER
Findings - roles
• Differing product lines, but various common themes in
operation.
• High manual content in 3 of the lines assessed out of the 4.
• Various types of manual function
– Skilled critical part of the production process, cannot be
replaced by automation without an impact on yield, long
training periods to acquire skills and speed required.
– Skilled hand ‘crafting’ within a production process
environment perceived as added value carrying ‘hand made’
branding.
– Multi skilled workers operating in various lower value roles
either similar or dissimilar across various production
processes within a single plant.
– Workers undertaking low value roles on production lines
with limited rotation.
CASPER
Findings – ergonomics
“RULA scores across all the observed production line tasks ranged
from 3, requiring further investigation to 6/7 (out of 10), (requiring further
investigation and changes to be made soon).
These scores equated to the majority of tasks presenting
low to medium levels of risk”, but with specific cases requiring action.
“Common tasks that were observed in all participating companies were
pick, place, inspection and packaging type tasks.
Across all companies these engaged similar physical actions”.
CASPER
Findings – ergonomics
“A large majority of tasks observed as part of this study, resulted in
workers adopting poor neck postures (flexed >25 degrees) which were
sustained for prolonged periods of time. These tasks were predominantly
tasks requiring inspection or placement of product components onto the
Lines”.
“Excessive reaching and twisting was often observed throughout tasks
conducted on all participating production lines, these actions were
typically conducted frequently at high rates of repetition. Excessive reaching
and twisting typically resulted from poor placement of the product on the
conveyor in relation to the worker, i.e. outside recommended reach distance.
This was often determined by the output mechanism of previous automated
process machinery or from trays of additional material being positioned
off to the side of the conveyor”. Hence process interaction is a critical aspect.
Findings – ergonomics
CASPER
30
25
20
15
10
5
Body part
Ankles/Feet
Knees
Hips/Thighs
Lower Back
Upper Back
Wrists/Hands
Elbows
Shoulders
0
Neck
“In total 49 production line workers
completed a questionnaire.
25% -30% of workers questioned
had some form of ache, pain or
discomfort that they attributed to
their work activities”
Percentage of workers reporting
discomfort/pain
“Evidence suggests that work cycle times shorter than 30 seconds, or
cycles where more than 50% of the cycle time is involved in the same
kind of motion pattern, are strongly related to disorders of the forearm
and wrist (Silverstein et al 1986).
Cycle times observed on the participating lines ranged from 1.3 to 46
seconds”
Conclusions - Ergonomics
CASPER
Based upon the scope of this assessment ergonomic issues do exist in the
Workplace. Some consideration is given to this, but probably not enough.
Means of improving this are :
• Greater human centred focus to activities in the workplace and
interaction with Production machinery and processes.
• More job rotation, and multi skilling to allow flexibility in the
plant, and variety of operation.
• Focus on processes and interaction between personnel and
machines to reduce reach and stretching, to reduce posture
problems, and lifting heavier objects.
• Conveyor and working surfaces at more optimum heights for
workers, where safe allow adjustable workstations, and seating.
• Involve employees more in the on going processes associated
with workplace Design and improvements.
CASPER
i.e Improved ‘job design’ by consideration and analysis in the job
definition process alongside the production process.
Methods to achieve this are :
•Evaluation of workload demands
•Task simulation
•Assessment of Physical actions required and rate of repetition
•Analyse recovery actions when system malfunctions
•Consider social interaction, personal workspace and worker self esteem
•More workforce involvement
·
•Recognise metrics associated with employee comfort in the workplace
more, as part of the business case for change, it is a significant hidden
cost in both the short and potentially long term.
CASPER
Findings - Automation
“Presentation of the food products for automation needs to be addressed
further.
Previous experience in other industries suggests that initially this can be done
with little/no cost and the better layout in terms of position and orientation
improve the efficiency and consistency of the overall handling process…
for automation to be successful it is essential that the basic principles of
orientation and positioning be developed as core line procedures.”
Vision, alignment and manipulator systems are applied, but need to be ‘more’
appropriate, and priced for the industry.
Findings - Automation
CASPER
•
Products can be categorised in to rigid and non rigid forms, e.g
Unpacked ham is non rigid, rigid - bread rolls, or some packed
products.
•
Automation of rigid products can apply technology transfer
using other recognised techniques.
•
Non rigid products are more difficult to automate because of
lack of databases of experience, and need for newer technology
to handle more complex products and variability.
•
The roles identified within CASPER are in many cases relatively
simple, and hence may be achieved by automation particularly where
skill and value associated is low.
•
Cycle times (1-3 sec), position, orientation and accuracy requirements
are well within the grasp of automation technology.
•
But cost, materials and reliability are critical issues
for acceptance
CASPER
Conclusions - Automation
• With many pick and place type roles automation can be applied
as a means of making efficiencies. This is a common theme
within the companies assessed, and need not result in overly
complex manipulation requirements.
• A cost effective automation/mechatronic approach could have
significant benefits
• A system with a target cost of up to £15,000 could open up a
new market, for the food and other sectors requiring light weight
reliable systems
• The new technology focussing on :
– rapid change of function
– control by non skilled workers,
– ability to rapidly align within the production process
are the key enabling technologies.
• Rapid change end effectors to support various functions
CASPER
Outline specification for a suite of modular units.
·
·
·
·
Number of Axes
:4
Reach
: 1m
Payload
: 1 – 2 Kg (including end effector)
Speed
: 1m/s
Accuracy
: +/- 1mm
System will need to be mobile, and easily located on to set positions on the production
line, where it can align itself with the production process and position of produce.
The system will be designed for hygiene, environment and lubrication requirements
that are applicable in the food industry.
Plastics will be used where appropriate to reduce weight and cost, and the design
Will Consider minimising the number of mouldings etc.
Programming is a major consideration, and Salford's ‘Virtual teach’ using
‘sensor glove’ techniques are proposed, as a means of enabling
Programming and rapid interchangeability of the unit.
CASPER
Phased technology development approaches
1.
2.
3.
4.
5.
An assessment phase to capture the specification requirements,
Simulation work to initiate the design process based upon the
motions required against product types.
Research on the simple programming system for the ‘robot’,
functions to be performed
•
•
•
Selection in the workplace to make the system moveable across functions
Integration with vision systems for location and control purposes,
Man machine interface (ergonomics) and safety
6. Detailed design and development,
7. Works and site trials of prototype hardware.
Further work is required with potential partners to develop the approach
In to an R&D programme
CASPER
Overall conclusion.
• The sector needs to consider ergonomic based metrics alongside
cost metrics within the planning and operations of the production
Facility to a greater extent.
• The application of low cost automation against the range of common
pick, place and pack functions needs to be researched further as
a potential R&D LINK project, providing affordable solutions.
CASPER
Combining the conclusions from the common automation and
Ergonomic studies generates two potential solutions to improve the
sector :
1. Provision of improved company or use of third party
evaluations within process and plant design covering :
–
–
–
2.
Ergonomic evaluation
Simulation of production process and human interaction
Application of ‘lean’ type techniques for layout
Technology developments to support low cost automation
solutions, ‘plug and play’, multi functional simply controlled
units operating within plants covering the high repetition low
value tasks.
–
An outline specification has been created.
CASPER
• For each participating company reports and recommendations
were made on each evaluation to provide a local opportunity for
change.
• Each company has been provided with the opportunity of
progressing the outcomes within a LINK project to consider low
cost automation solutions focussing on :
– Lower value jobs
– Common or near common functions
• Creating potential multi company exploitation of common
Technology programme.
• Considerable potential savings from direct costs of employment,
improved efficiency, hidden costs from staff turnover and ergonomic
Issues.
CASPER
Way forward …..
• As a result of the work undertaken through CASPER Integrated services for ergonomic and production process improvement
are available from INBIS, Loughborough and Salford University.
These can be applied to new design or improvement of the production
facilities, and reduce ergonomic and safety related problems.
• The opportunity to develop a low cost automation solution remains, and
needs to be opened to a wider market in the sector.