Automated
Assembly & Testing in Medical Device Production
A road map of the key issues
to consider when sourcing complex integrated assembly & testing
systems
Featured in Medical Device Technology October 2002
Unpacking the complexities
The larger pharmaceutical and medical device manufacturing companies
are increasingly realising that by developing novel drug delivery
mechanisms, the life of a drug can be significantly extended. This,
combined with the development of other complex medical devices requiring
volume-production methods, has led to an increase in the use of
combined assembly and testing systems. These systems integrate the
use of assembly processes with sophisticated testing procedures
that require specialist automated assembly and data handling. This
article outlines the key issues to address when sourcing this equipment.
Capturing the requirements
It is often difficult
for system integrators to properly capture the manufacturers
requirements for an automated production system. Sometimes, this
is because a minimal specification is supplied and essential information
has to be coaxed out of the manufacturer. At the other extreme,
the enquiry consists of two pages of technical specifications hidden
within a forest of commercial, contractual and general specifications,
which confuse the assessment of the requirements.
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Pallet-based plastic component assembly
in an automotive application
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Estimating volumes
When considering an automated production process, it can be difficult
to estimate peak volumes. This is particularly the case with a new
product start-up when the marketing data is variable. The techniques
used for automated assembly may be considerably different for manufacturing
1 part/min on a single day shift compared with 1 part/s in a 24/7
regime. Although difficult to assess, it is essential to have a
clear goal related to production volumes.
Identifying basic physical operations
A system integrator needs to quickly gain an overall understanding
of the production process to ensure that it matches the requirements.
The following allows a swift response from a potential supplier:
- A clear definition of the required assembly process actions,
preferably in diagrammatic form
- The allowed time to produce one part, for example,3/s or
1/min.
- A completed assembly drawing or sketch.
- Component drawings with tolerances, if possible.
- A description of the method of presentation of each component
part to the system, for example, loose in a box, on a conveyor,
pumped or in a tray.
- Details of how the finished assemblies are to be presented
or packaged.
Requirements for product verification
Next the requirements for product identification and verification
can be evaluated. The extent of work in this area will depend on
the cleanliness classification and validation requirements of the
production environment. Some processes do not require verification
of component parts as they enter the automated system. Most subcomponents
that carry a drug must be uniquely identified and this must be recorded
as the unit enters the process. More often today, parts not containing
drugs must be checked as being present using Poka Yoke techniques.Poka
Yoke is Japanese for mistake proofing that involves 100% automatic
sensing of all components individually and together to check the
assembly.
A clear description of how the parts can be identified and how
the information is to be logged or verified is essential to the
design of the control elements of the automated system. Automated
processes are moving to 100% traceability of the finished parts,
therefore, labeling and data-storage requirements need to be defined
and communicated to the system integrator. The control information
specifically relevant to data handling and verification will require
knowledge of automated manufacturing practices, GAMP 4,and the requirements
of the Food and Drug Administrations Title 21 Code of Federal
Regulations, Part 11.
The search for the right solution
A considerable investment in time is required to properly understand
the specific requirements and to formulate the most suitable solution.Even
with a clear route to communication between the system integrator
and the manufacturer, this can run into many months of work for
both sides just to be able to determine the correct solution.Before
a dialogue begins, it is important that the manufacturer satisfies
himself that the potential supplier of the equipment is capable
of working to the required standards.Quality systems standards such
as ISO 9001/2000 and quality system requirements,QS 9000,are useful
benchmarks for selecting system integrators with experience in industries
outside the medical manufacturing industry.
Scope of project expertise
When sourcing an integrated system, manufacturers may also wish
to investigate the extent to which the system integrator performs
the separate aspects of design,manufacture and assembly in relation
to the mechanical,electrical and software/control aspects of the
project. Most manufacturers would like all of these elements to
be directly performed by permanent staff within the system integrators
company to ensure the timely completion and proper support of the
machine or system once it is in service. Some system integrators
subcontract major elements of software,control panel wiring or manufactured
parts.In addition, a supplier must be able to support the system
from concept,through manufacture, assembly,capability/commissioning
and into production.
Additonal assistance
There is no one single route to selecting the correct system.Selection
must be on a case-by-case basis,matching the requirements of the
assembly system.In the future,there may be some assistance in assembly
system design and specification. There are currently (at time of
publication) two research programmes in this area.The first is a
European Union thematic programme called Assembly-Net, which is
a discussion forum on assembly system design,manufacture and use.
The second is a project under the Eureka Factory mechanism called
E-Race that is just about to start. E-Race is attempting to develop
an interactive website for requirements capture and design of flexible
assembly systems
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