Information for Regulatory Compliance and Business Performance Improvement
Medical Device Design Control, Medical Product Design
When considering design controls for the medical device industry, you immediately
think of the FDA and medical devices, the European “CE” Mark, the various international
regulations on medical device guidance, etc.. On this page we shall specifically
focus on the FDA Design Controls, outlined in the CFR’s.
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Introduction: In the following document, we shall provide an outline to the FDA Quality
System Requirements for Design Controls and review requirements for Design Input,
Design Output, Design Expectations and Regulations.
The design controls section 820.30 of the FDA Quality System Regulation applies to
the design of products, and processes and changes to existing designs and processes.
Changes to existing designs should be made in accordance with design control requirement
even if the original design was not subject to these requirements. Design controls
are not retroactive to completed portions of ongoing design programs.
Overview- “When”- Stage 1 (a short history !)
Stage 1- On June 1, 1997, approximately 1 year after rule is published in the Federal
Register, all elements of the final rule become effective. However, with respect
to § 820.30, as long as manufacturers are taking reasonable steps to come into compliance,
FDA will implement a special 1-year transition program where official agency action
will not be initiated, including Form 483 observations, warning letters, or enforcement
cases, based on failure to comply with § 820.30.
“When”- Stage 2
Under stage two, June 1, 1998, FDA treats non compliance with design control requirements
in § 820.30 the same as non compliance with other provisions of the cGMP regulation.
i) “Device Recalls: In a study of quality problems”- 44% of recalls were due to design
ii) Software Related Recalls- 90% of software-related design failures were design
iii) Design Controls will avert on average 40 deaths and 600 serious injuries (per
iv) Harmonization, EN ISO 13485
Definitions - Specific Terms
Design History File (DHF) means a compilation of records which describes the design
history of a finished device.
Design Input means the physical and performance requirements of a device that are
used as a basis for device design.
Design Output means the results of a design effort at each design phase and at the
end of the total design effort. The finished design output is the basis for the
device master record. The total finished design output consists of the device, its
packaging and labeling, and the device master record.
Design Review means a documented, comprehensive, systematic examination of a design
to evaluate the adequacy of the design requirements, to evaluate the capability of
the design to meet these requirements, and to identify problems
Device History Record (DHR) means a compilation of records containing the production
history of a finished device.
Device Master Record (DMR) means a compilation of records containing the procedures
and specifications for a finished device.
Establish means define, document (in writing or electronically), and implement.
Where Appropriate means it is deemed to be appropriate unless the manufacturer can
document justification otherwise.
General principles of software validation guidance:
Unless specifically exempted in a classification regulation, all medical device software
developed, regardless of its device class, is subject to applicable design control
provisions of 21 CFR 820.30. This includes completion of current development projects,
all new development projects, and all changes made to existing medical device software.
Specific requirements for validation of device software are found in 21 CFR 820.30(g).
In addition, formal design reviews and software verification are integral parts
of an overall software validation, as required by 21 CFR 820.30(e) and (f).
Quality System Regulation
Subpart C -- Design Controls - 820.30 Design Controls
(1) Each manufacturer of any class II or class III device, and the class I devices
listed in paragraph (a) (2) of this section, shall establish and maintain procedures
to control the design of the device in order to ensure that specified design requirements
Human Factor Implications of the GMP Rule
The following are design control excerpts that relate to human factors:
(c) Design input: "Each manufacturer shall establish and maintain procedures to
ensure that the design requirements relating to a device are appropriate and address
the intended use of the device, including the needs of the user and patient."
– Human factor relevance: Manufacturers need a process that ensures adequate consideration
of human factors in the design and development of medical devices.
(f) Design verification and validation: "Design validation shall ensure that devices
conform to defined user needs and intended uses."
– Human factor relevance: Meeting user needs requires that the user-device interface
be designed such that it can be operated safely by the users of the device, and that
adequate precautions have been taken in the design of the device such that user error
Design & Medical Device Development Planning
820.30(b) Design and development planning.
– Each manufacturer shall establish and maintain plans that describe or reference
the design and development activities and define responsibility for implementation.
– The plans shall identify and describe the interfaces with different groups or activities
that provide, or result in, input to the design and development process.
– The plans shall be reviewed, updated, and approved as design and development evolves.
The plan ensures that the design process is appropriately controlled and the device
quality objectives are met.
Typical Plan Elements Include:
– Description of the goals and objectives of the design and development program;
i.e., what is to be developed;
– Delineation of organizational responsibilities with respect to assuring quality
during the design and development phase, to include interface with any contractors;
– Identification of the major tasks to be undertaken, deliverables for each task,
and individual or organizational responsibilities (staff and resources) for completing
– Scheduling of major tasks to meet overall program time constraints;
– Identification of major reviews and decision points;
– Selection of reviewers, the composition of review teams, and procedures to be followed
– Controls for design documentation;
– Notification activities.
820.30(c) Design input.
Each manufacturer shall establish and maintain procedures to ensure that the design
requirements relating to a device are appropriate and address the intended use of
the device, including the needs of the user and patient.
The procedures shall include a mechanism for addressing incomplete, ambiguous, or
The design input requirements shall be documented and shall be reviewed and approved
by designated individual(s).
The approval, including the date and signature of the individual(s) approving the
requirements, shall be documented.
Design Input Comment.
Design input is the starting point for product design. The requirements which form
the design input establish a basis for performing subsequent design tasks and validating
the design. Therefore, development of a solid foundation of requirements is the single
most important design control activity.
Incomplete requirements can have an adverse on the design process.
If essential requirements are not identified until validation, expensive redesign
and rework may be necessary.
CONCEPT DOCUMENTS VERSUS DESIGN INPUT Marketing memoranda & customer concept documents
are not the intent of the QSR. The intent is for product conceptual description
to be elaborate, expanded and written with an Engineering level of detail.
RESEARCH AND DEVELOPMENT - Should not equate prototype design with finished product
RESPONSIBILITY FOR DESIGN INPUT DEVELOPMENT
Product developers who understand the auxiliary issues that must be addressed, as
well as the level of detail necessary to design a product.
A key principle is that the product developer(s) ultimately bear responsibility for
translating user and/or patient needs into a set of requirements which can be validated
prior to implementation.
Primarily a design function, however design input requirements encompass inputs from
production, quality, key suppliers, and the user. Reduces assumptions on part of
Scope and level of detail:
Design input requirements must be comprehensive and generally fall into three categories.
– Functional requirements specify what the device does, focusing on the operational
capabilities of the device and processing of inputs and the resultant outputs.
– Performance requirements specify how much or how well the device must perform:
speed, strength, response times, accuracy, limits of operation, etc. This includes
a quantitative characterization of environment: temperature, humidity, shock, vibration,
& EMC. Reliability and safety fit here.
– Interface requirements specify characteristics which are critical to compatibility
with external systems; specifically, those characteristics which are mandated by
external systems and outside the control of the developers. One interface which is
important in every case is the user and/or patient interface.
Assessing Inputs for Adequacy.
The design input must be reviewed for adequacy. After approval, the design input
becomes a controlled document. All future changes will be subject to change control
Any assessment of design input requirements boils down to a matter of judgment.
Review team should be multidisciplinary and have appropriate authority.
A number of criteria may be used by the review team.
– Design input requirements should be unambiguous.
– Qualitative limits should be expressed with associated tolerance.
– The set of requirements should be self-consistent, no conflicts.
– Environment for use should be properly characterized.
– Cited standards should be reviewed for completeness & relevance.
Evolution of Design Inputs.
Initial set of requirements, covering overall product, most difficult to develop.
As design proceeds, early stage output becomes input for subsequent stages. Information
becomes more extensive and detailed.
Design changes to correct one problem may create new problem. Change control becomes
From a design control perspective, the number of requirement changes is less important
than the thoroughness of the change control process.
820.30(d) Design output.
Each manufacturer shall establish and maintain procedures for defining and documenting
design output in terms that allow an adequate evaluation of conformance to design
Design output procedures shall contain or make reference to acceptance criteria and
shall ensure that those design outputs that are essential for the proper functioning
of the device are identified.
Design output shall be documented, reviewed, and approved before release.
The approval, including the date and signature of the individual(s) approving the
output, shall be documented.
820.3(g) Design output means the results of a design effort at each design phase
and at the end of the total design effort. The finished design output is the basis
for the device master record. The total finished design output consists of the device,
its packaging and labeling, and the device master record.
§ 820.3(y) Specification means any requirement with which a product, process, service,
or other activity must conform.
Design Output Comments.
The quality system requirements for design output can be separated into two elements:
Design output should be expressed in terms that allow adequate assessment of conformance
to design input requirements and should identify the characteristics of the design
that are crucial to the safety and proper functioning of the device. This raises
two fundamental issues for developers:
– What constitutes design output? An item is design output if :
it is a work product, or deliverable item.
a design task listed in the design and development plan.
the item defines, describes, or elaborates an element of the design implementation.
– Are the form and content of the design output suitable?
Design Output Examples.
Descriptive materials which define and characterize the design.
– Block diagrams
– Flow charts
– Software high-level code
– System or subsystem design specifications
Production Specifications include drawings and documents used to procure components,
fabricate, test, inspect, install, maintain, and service the device, such as the
– assembly drawings
– component and material specifications
– production and process specifications
– software machine code (e.g., diskette or master EPROM)
– work instructions
– quality assurance specifications and procedures
– installation and servicing procedures
– packaging and labeling specifications, including methods and processes used.
– the results of risk analysis
– software source code
– results of verification activities
– bio-compatibility test results
– bio-burden test results
820.30(e) Design review.
– Each manufacturer shall establish and maintain procedures to ensure that formal
documented reviews of the design results are planned and conducted at appropriate
stages of the device's design development.
– The procedures shall ensure that participants at each design review include representatives
of all functions concerned with the design stage being reviewed and an individual(s)
who does not have direct responsibility for the design stage being reviewed, as well
as any specialists needed.
– The results of a design review, including identification of the design, the date,
and the individual(s) performing the review, shall be documented in the design history
file (the DHF).
Design Review Purpose
In general, formal design reviews are intended to:
– provide a systematic assessment of design results, including the device design
and the associated designs for production and support processes;
– provide feedback to designers on existing or emerging problems;
– assess project progress; and/or
– provide confirmation that the project is ready to move on to the next stage of
Number & Type of Reviews
Number depends on complexity.
Control of the design review process is achieved by developing and implementing a
formal program consistent with the QSR.
Procedures should detail resolution of concerns and tracking of corrective actions.
Early reviews deal with design input requirement, followed by evaluation of solutions
to design issues, then material & manufacturing method related and finally verification,
validation & production issues will dominate.
l 820.30(f) Design verification.
– Each manufacturer shall establish and maintain procedures for verifying the device
– Design verification shall confirm that the design output meets the design input
– The results of the design verification, including identification of the design,
method(s), the date, and the individual(s) performing the verification, shall be
documented in the Design History File.
Verification activities are conducted at all stages and levels of the device design.
The basis of verification involves a three-pronged approach involving:
– inspections and
Types of Verification Activities
Worst case analysis of an assembly to verify that components are derated properly
and not subject to overstress during handling and use.
Thermal analysis of an assembly to assure that internal or surface temperatures do
not exceed specified limits.
Fault tree analysis of a process or design.
Failure modes and effects analysis.(Result Table)
Package integrity tests.
Bio-compatibility testing of materials.
Bioburden testing of products to be sterilized.
Comparison of a design to a previous product having an established history of successful
820.30(g) Design validation.
– Each manufacturer shall establish and maintain procedures for validating the device
– Design validation shall be performed under defined operating conditions on initial
production units, lots, or batches, or their equivalents.
– Design validation shall ensure that devices conform to defined user needs and intended
uses and shall include testing of production units under actual or simulated use
– Design validation shall include software validation and risk analysis, where appropriate.
– The results of the design validation, including identification of the design, method(s),
the date, and the individual(s) performing the validation, shall be documented in
the Design History File.
820.3(z) Validation means confirmation by examination and provision of objective
evidence that the particular requirements for a specific intended use can be consistently
– 1 Process Validation means establishing by objective evidence that a process consistently
produces a result or product meeting its predetermined specifications.
– 2 Design Validation means establishing by objective evidence that device specifications
conform with user needs and intended use(s).
§820.3(aa) Verification means confirmation by examination and provision of objective
evidence that specified requirements have been fulfilled.
Design Validation Comments
Design validation is a cumulative summation of all efforts to assure that the design
will conform with user needs and intended use(s), given expected variations in components,
materials, manufacturing processes, and the use environment.
Validation Planning should begin early in the design process and should:
– Identify performance characteristics
– Describe validation methods
– Define acceptance criteria
– ensure that the user needs & intended uses are addressed (human factors)
– address packaging & labeling.
VALIDATION REVIEW may expose deficiencies in the original assumptions concerning
user needs & intended uses. A formal review process should be used to resolve any
such deficiencies. As with verification, the perception of a deficiency might be
judged insignificant or erroneous, or a corrective action may be required.
– Not all devices require clinical trials but all require clinical evaluation.
– Tested under actual/simulated use conditions.
– Use testing, inspection, literature search, historical evidence,
– Pilot product OK, but should simulate actual manufacturing process.
– Should include exposure to; shipping, temp, RH, shock, corrosive atmosphere, sterilization,
820.30(h) Design transfer.
– Each manufacturer shall establish and maintain procedures to ensure that the device
design is correctly translated into production specifications.
Transfer procedures should address
– First, the design and development procedures should include a qualitative assessment
of the completeness and adequacy of the production specifications.
– Second, the procedures should ensure that all documents and articles which constitute
the production specifications are reviewed and approved.
– Third, the procedures should ensure that only approved specifications are used
to manufacture production devices
820.30(i) Design changes.
– Each manufacturer shall establish and maintain procedures for the identification,
documentation, validation or where appropriate verification, review, and approval
of design changes before their implementation.