The Emergence of CSA: A Shift in Paradigm
Computer Software Assurance (CSA) emerges as a transformative force in software validation. It challenges the traditional CSV methodology and introduces a more flexible and efficient approach based on tailored validation efforts. The essence of CSA lies in prioritizing critical thinking, assurance needs, testing, and documentation, in that sequence. Documentation remains a vital part of the process, but CSA aims to promote patient safety by emphasizing critical thinking in the validation process. The aim is to ensure delivery of a high-quality, safe product that meets patient needs, rather than robust documentation that passes an audit cycle.
CSA operates as a risk-based approach, aiming to establish software suitability for its intended purpose while optimizing the validation process. It follows a least-burdensome approach, ensuring that the validation efforts align with the associated risks.
In its draft guidance on CSA, The U.S. Food and Drug Administration (FDA) provides a general approach for CSA, which involves the following steps:
- Determining whether the software is intended for use as part of the production/quality system.
- Evaluating the level of risk if the software was to fail to perform as intended.
- Identifying assurance activities commensurate with the risk.
- Capturing sufficient evidence to demonstrate that the software was assessed and performs as intended.
This approach focuses on building confidence through the testing of high-risk functions. Since most applications consist of a mix of standard, off-the-shelf, and configurable or customizable elements, CSA encourages software categorization at the function level. This ensures that validation efforts are tailored to the specific needs of the software.
Furthermore, the CSA methodology encourages users to take advantage of technology that wasn't available 20 years ago, like cloud computing and validation management software, as well as rely on the vendor’s existing documentation.
A Practical Overview of CSA
In practice, Computer Software Assurance (CSA) operates as a risk-based strategy to ensure that software aligns with its intended purpose. It involves assessing potential risks to the safety and quality of a device and determining the level of assurance needed. This approach is adaptable and flexible, adjusting the rigor of validation activities to the assessed level of risk.
The process of establishing computer system assurance comprises four key steps:
1. Identifying the intended use: The level of assurance required for a computer system depends on its intended use, with higher assurance necessary for systems closely linked to production or quality control.
2. Determining the risk-based approach: A risk-based analysis is used to assess the appropriate assurance activities, considering the potential impact of software failures on medical device safety.
3. Determining appropriate assurance activities: The level of rigor for assurance activities aligns with the level of risk, with higher-risk software requiring more comprehensive testing and evidence collection.
4. Establishing an appropriate record: Manufacturers maintain records that encompass the software's intended use, risk level, and documentation of assurance activities performed.
In Figure 2 below, a schematic representation of CSA steps can be seen.