Manufacturers of medical devices are required by federal law to validate software that is part of the manufacturing or quality system. But there is confusion about what this means. What software does the FDA regulate? What level of validation is required? There are no checklists available from the FDA. However, an Association for the Advancement of Medical Instrumentation (AAMI) workgroup has been formed to write a technical information report on the topic of software validation for regulated automated process software. This AAMI report will address in detail some of the issues that are discussed here in a simplified form. Meanwhile, there is good documentation that offers guidance.
The FDA is good about producing documents that interpret and elaborate on federal regulations it is charged with enforcing. It is useful to look at the regulatory origins to understand what is law and how it differs from the guidance information that the FDA produces to interpret the law.
The federal regulation specifically applying to this software is found in the section on production and process controls. Section 21 CFR 820.70 (i) states: “When computers or automated data processing systems are used as part of the production or the quality system, the manufacturer shall validate computer software for its intended use according to an established protocol. All software changes shall be validated before approval and issuance. These validation activities and results shall be documented.”
The FDA’s January 11, 2002 document titled “General Principles of Software Validation; Final Guidance for Industry and FDA Staff” (GPSV) includes a section (Section 6) that interprets this regulation. Let’s look at how to apply this interpretation.
Is It Regulated?
Medical device manufacturers should inventory all software used in a production, research, engineering, sales, or support facility. That inventory should include the “intended use” for each software item. If the software item is used to monitor or control part of the manufacturing process or part of the quality system, it falls within the regulation. Software used to automate the quality system may include software in three general categories.
- Software used in the design and development of medical devices such as CAD systems, compilers, test software, simulators, and code generators
- Software used in the creation, maintenance, and control of quality data about medical devices such as complaint-handling systems, lot-tracking systems, training systems, QC systems, and patient-tracking systems, or software used to control the quality such as production monitoring, and control software
- Software used in the creation, maintenance, reporting, validation, and storage of electronic records and electronic signatures
Unregulated software can fall under the requirements of 820.70 (i) by its association with other regulated software. A software item that is normally considered unregulated under these guidelines might produce data that is used by regulated software. The validation requirements of 820.70 (i) then apply to that (formerly unregulated) software item. The validation requirements in this case could be focused on the functionality of the formerly unregulated software related to the creation, storage, manipulation, and security of the data used by the regulated software.
Components of Validation
It is a common misconception that validation is synonymous with testing. The GPSV makes it clear that validation includes testing, but validation might also include many other components that lead to the conclusion that the software is fit for its intended use. Depending on the intended use, some or all of these components might be appropriate for a given software item.
Below is a look at what validation includes and advice on handling each component that is included.
- Determination of the software lifecycle: The life cycle of a piece of software internally developed by the medical device manufacturer is different from software embedded in a production tool purchased by the manufacturer. Determine what the lifecycle will look like to facilitate planning of validation activities at each phase of the lifecycle.
- Document intended use: The intended use of the software item is similar to a product-level or user level requirement. Itemize the functions, especially the QSR regulated functions, you expect the software to perform.
- Risk analysis and risk management: Think about how failure of a software item would impact the medical device itself. Do this by considering a failure of each of the functions of your intended use document. If the impact on the device could adversely affect patient safety, it’s an indication that you need to do more to validate this software than you would for one that has a less severe impact. Managing risk includes the identification and implementation of risk control measures. These might include manual or automated checking for failures of the software item. Verification of the output of a software-automated process is a form of validation and in many ways is better than simply testing the software at a single snapshot in time. If enough risk control measures are put in place so that the residual risk is reduced significantly, the remaining validation tasks may be reduced. When dealing with electronic records or signature systems, consider regulatory risks — risks of not having required records available for the FDA — and security risks.
- Configuration management and version control: A configuration management plan should be in place for each software item. Consider who will make the decisions about upgrading the software, who will supply the upgrades, who will install the software, and who will take responsibility for re-validating before it goes online. Consider also any other items in your process that might be incompatible with new versions of the software item and how that incompatibility will be detected and resolved.
- Planning: Quality plans and software-verification and-validation plans detail the tasks and deliverables related to an individual software item or the collection of software items that make up an automated process. Plans should cover activities, roles, responsibilities, and resources for each phase of the lifecycle.
- Technical evaluations and management reviews: Determine if the software is technically up to the intended use before putting it online in technical evaluations. Management reviews should reference the output of the tech evaluations and also consider if the residual risk of a failing software item is acceptable prior to deployment of the software. Management also needs to consider whether the users of the software are trained sufficiently to successfully deploy the software. The management review should be considered the final gate to deployment.
- Testing: Focus testing on existing risk control measures and then on functionality of the software whose failure could lead to severe consequences. There is little value in testing functions of the software that have little effect on the manufactured device. For electronic record systems, focus testing on functions whose failure could result in record loss, alteration, or loss of security.
- Traceability: You’ll need some documented trace to show that all the functionality detailed in the intended-use document was implemented or acquired. Furthermore, any risk control measures identified in your risk management report must be traced to where they are implemented and where its ability to mitigate risk was tested. Finally, functional testing of the software should be traceable back to software requirements or intended-use functionality.
How Much Is Enough?
The GPSV states: “The level of validation effort should be commensurate with the risk posed by the automated operation. In addition to risk, other factors, such as the complexity of the process software and the degree to which the device manufacturer is dependent upon that automated process to produce a safe and effective device, determine the nature and extent of testing needed as part of the validation effort.”
The FDA does not give further advice to distinguish which validation components should be part of a reduced validation effort and which components should be part of a maximum validation effort. The following guidelines are useful as a first pass at determining appropriate validation efforts for regulated automated process software. Every manufacturer’s situation is different, and these guidelines should be tailored to the FDA device class and regulatory environment. Part of a quality plan or validation plan for managing automated process software should include the manufacturer’s version of the following guidelines.
Guideline #1: Validation Components for Very Low Risk Software Items
Although not specifically dictated by the FDA, certain components of validation should be completed for any validated software item. This minimal subset may be adequate for very low risk software items. Very low risk software items are those whose failure poses a very low risk of affecting the quality of the device being produced or poses a low risk of adversely impacting the integrity or security of quality records required by the FDA.
- The intended use of the software item must be documented to understand dependence of the manufacturer’s production or quality system on the software item.
- The risk analysis component must be completed, if for no other reason than to determine how much more validation is required. The GPSV suggests that the level of validation effort is related to the risk posed by the use of the software item. This determination is made in the risk analysis task.
- Configuration management also needs to be considered on each software item. At a bare minimum, the validation report should detail the version of the software item that was validated, the hardware configuration on which it was validated, and the version details of any associated software components that are required for the operation of the software item. Associated software components could include operating systems or PC-based user interfaces for an embedded software item. Concerning spreadsheets, the version of the spreadsheet being validated must be controlled, and the version of the spreadsheet program (e.g., Excel) on which the spreadsheet was validated must also be controlled.
Guideline #2: Validation Components for Medium Risk Software Items
All validation components present for low risk software items are included for medium risk items. Additionally, the following should be addressed.
- Risk management activities should be included. If the risk analysis concluded that there were moderate risks in using the software item, then some type of reduction of the risk should be considered. Risk management can reduce the likelihood of an adverse event related to the use of the software, or can reduce the severity of the adverse event, or can reduce both.
- Traceability should be used to provide objective evidence that risk control measures were implemented and tested for effectiveness.
- Testing components should be added to test the effectiveness of any risk control measures that were implemented as part of the risk management process. High risk functions in the intended use of the software item should also be tested thoroughly to provide some level of assurance that the high risk failures are not likely to occur.
- Management reviews should be added as part of the validation process. They should examine the risk management plans in order to consider the residual risk after risk control measures are in place and to determine if the residual risk is acceptably low to approve deployment of the software item.
Guideline #3: Validation Components for High Risk Software Items
All validation components for low and medium risk software items are included for high risk items. Additionally, the following should be included.
- There should be a detailed life cycle definition for the software, plus a quality plan and verification-and-validation plan detailing quality and validation activities for each phase of the life cycle.
- If the manufacturer develops the software item, requirements should be expanded from the intended-use requirements to formal software requirements. If the software item is purchased from a vendor, then a technical audit should be conducted to assure that good design practices were followed and that vendor-maintained detail requirements are traceable to verification tests.
- Technical evaluations should be conducted throughout the life cycle.
- Testing should be expanded from intended-use testing to full requirements verification. Some attention to unit-level testing and integration level testing of the critical functions of the software should be considered. If software is acquired from a vendor, audit for test results and known defects.
This breakdown of validation efforts – commensurate with the risk of using a software item – represents only one approach. Manufacturers should use it as a template and make adjustments where necessary. There are many ways to get the job done. They can be defended if the logic behind the plans is consistent and the plans are adequately documented.