Overview of Quality
Management System
(QMS)Yan Chia
November 2021
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Investigate – equipment, process, materials
How to solve the problems?
Quality Objectives
Process & Production Control
Customer Requirements Procedures &
Work InstructionsTraceability – Lot Number Supplier Quality
Design Control
Risk Management Inputs / Outputs Verification & Validation
Change Management
Change Management Risk Review
Resources
Training Work EnvironmentInfrastructure
Corrective & Preventive Action
Manage Non-conformities Verify EffectivenessProcess Improvement
Product Surveillance
Complaint Handling VigilanceRisk Monitoring
Management Responsibility
Management Review Internal AuditInspection Readiness
Happy customers!
Happy staff!
Happy boss!
5 stars review!
Advantages of QMS
How to implement QMS to a
MedTech Company?
Legislative Hierarchy
Formal, broad description of the
law (mandatory)
Support the Act, providing more detailed
information (mandatory)
Provide guidance to comply with and
achieve goals imposed in regulations
(mandatory if referenced by an Act or
Regulation. Otherwise, voluntary)
Provide guidance to comply with and
achieve goals imposed in standards
(voluntary)
Criteria within an industry (mandatory if
referenced by an Act or Regulation.
Otherwise, voluntary)
Regulations & Standards
ISO 13485 – Medical Devices QMS
FDA 21 CFR Part 820 – Quality System Regulation
EU MDR – European Medical Device Regulation
IEC 62304 – Medical device software – Software life cycle processes
IEC 62366-1 – Medical Device Usability Engineering
ISO 14971 – Risk Management
Document System Hierarchy
Describes the QMS & Policy
Describes the processes of the QMS
Used to record the data
Provide detailed information pertaining
to specific events or a series of related
events
Describes the tasks within the processes
Therac-25 Incident
1985 – 1987
Therac-25
What Happened?
June 1985
Katie Yarborough, 61
200 Rads
Medical Physicist, Tim Still
PDP-11 Computer
1990
2nd incident
June 1985
Ontario, Canada
3rd incident
Yakima, Washington
4th incident
Tyler, Texas
5th incident
1986
6th incident (final)
1987
Fritz Hager
Malfunction-25 =
Overdose/ Underdose
Unknown
“dual-mode” radiation-
therapy machines
Electron Mode
X-Ray Mode
Therac-20
Hardware Interlock
Assembly
What happened next?
The FDA declared the Therac-25 DEFECTIVE
AECL issued software patches and hardware updates which
eventually allowed the machine to return to service
The lawsuits were settled out of court
The problems were solved until…
Another problem
January 1987
Counter-overflow
Unscanned Beam & Overdose
Patient died 3
months later
Where is the responsible
programmer?
Who’s fault?
The programmer?
The Manager?
The Business Owner?
Never Blame People,
Blame the System
Root cause - Company’s system problem
Software requirements and design documentation were written as an after-
thought
No quality systems in place to control the design and development of software
Inadequate testing
Only system-level software testing was performed
No unit level or integration level testing was evident
No plan for regression testing of all software changes
Software’s user interface was confusing to the user
Error messages were cryptic
User manual was difficult to understand – no explanation of the error codes or any
guidance for the user when error codes were displayed
Root cause - Company’s system problem
Risk assessment
Only performed risk assessment for hardware, not software
Removed the interlock (fuse) in the hardware without doing risk assessment
Assume product is safe purely because prior generation was safe
Design issue
Lack of defensive design (no adequate cross checks, error detection, and error-
handling capabilities)
E.g., when the error message pops up, it should stop the machine from functioning
until certain action is in place
Inadequate investigations or follow-up on complaints
Root cause - Company’s system problem
Resources
Programmer did not have experience in the Assembly language
Engineers did not have sufficient training
What happened to AECL?
What happened to AECL?
Therac-25 discontinued, recalled
AECL dissolved AECL Medical in 1988 and renamed it Theratronics
International Ltd
No longer makes linear accelerators
Despite passing repeated Canadian safety inspections, the company
has suffered through an FDA ban on all its medical equipment from
1991 to 1994
Changes to the FDA since then
Define more requirements to regulate medical devices, focus on
software
Power to inspect the work of manufacturers, ask manufacturers to
recall products, issue injunctions against distribution of products if
non-compliant
Issue guidance documents
This incident also have an impact on other federal agencies including
the US Federal Aviation Administration and Nuclear Regulatory
Commission – these agencies also govern software-development
practices like the FDA
Case study gives us the opportunity
to learn from past mistakes
Over 35 years later, some companies
are still struggling with many of the
same issues as the Therac-25 incident
An effective QMS will reduce the
product risk to the patient, user and
company
The QMS wouldn’t work by just relying
on a single person in an organisation
It will only work if everyone is trained
and comply with the QMS