assembly and testing in medical device production
A road map of the key issues to
consider when sourcing complex integrated assembly and 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.
||Pallet-based plastic component assembly in an automotive
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
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
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
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.1
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
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 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
1 For information on Poka Yoke: www.keyence.co.uk/topics/poka_yoke_kaizen/guide.html
Feel free to contact TQC using the links