R-TF-025-001 Usability plan
Table of contents
- Purpose
- Scope
- Use specification
- Identification of characteristics for safety and possible use errors
- Identification of known or foreseeable hazards and hazardous situations
- Identification and Description of Hazard-related Use Scenarios
- Selection of hazard-related scenarios for Summative Evaluation
- Documentation of the User Interface specification
- User interface evaluation plan
- Design and Formative evaluation
- Summative evaluation
Purpose
The usability plan demonstrates that the device user interface is safe and effective for the intended users, uses, and use environment.
Scope
This usability plan describes the different usability activities carried out throughout the entire product life cycle of the device Legit.Health Plus (hereinafter, the device).
This usability plan stems from the general procedure GP-025 Usability and Human Factors Engineering. The general procedure explains the relationship between usability and risk assessment, the criteria for usability acceptability and the general proccess.
This plan will be reviewed, updated, and approved according to changes in design and development.
The usability plan covers the following items:
- Names of the persons and assignment of responsibilities including approvals of documentation tasks
- Planned usability activities and a description of the activities in each life-cycle stage of the medical device
- Links of the usability process with the risk management process
- Links of the usability process with the software development process
- Definition of a selection criteria for hazard-related scenarios to evaluate in summative evaluation
Relationship between FDA and IEC 62366-1:2020
As explained in the general procedure GP-025 Usability and Human Factors Engineering, the usability process will be conducted according to IEC 62366-1:2015 standard and FDA guidance document Applying Human Factors and Usability Engineering to Medical Devices. The equivalence of requirements between the two documents is detailed in the general procedure.
Relationship between usability and risk management
As explained in the general procedure GP-025 Usability and Human Factors Engineering, the usability process is closely linked to the risk management process. The input and output relation is explained in the general procedure.
Use specification
The use specification is a high-level statement, which contains the information necessary to identify:
- the user groups that are going to be subject to the usability process,
- the use environment that is going to be examined,
- the medical indications that need to be further explored.
The use specification being part of the global software development process will be established and formalized in the Software Development documentation.
Identification of characteristics for safety and possible use errors
The principal characteristics of the device will be identified by conducting a task analysis based on the overall description of the software. A list of tasks and sub-tasks describing the device's main functions will be used to establish a set of the device use scenarios.
Based on these scenarios and the data from the user research carried out to establish the use specification, a set of potential errors linked to the use of the device will be established. Work sessions to identify these potential errors will be held between JD-005, JD-003, JD-004 and JD-007.
These potential usage errors will be used to identify risks linked to the use of the device. These risks will be included in the global risk matrix and treated appropriately.
The tasks constituting the hazard-related scenarios are considered critical tasks as their incorrect performance would lead to potential harm for the patient (i.e. harm meaning: loss of time leading to a loss of the opportunity to be diagnosed or treated as soon as possible).
These use scenarios, critical tasks, potential errors, and associated risks will be gathered and documented in R-TF-025-002 Identification of characteristics for safety and possible use errors.
Identification of known or foreseeable hazards and hazardous situations
According to the usability process (see above), all the foreseeable hazards and hazardous situations will be recorded in the global risk matrix in the usability section and treated appropriately.
Identification and Description of Hazard-related Use Scenarios
These elements will be documented in the risk analysis file folder since the hazards, the sequence of events, and the harms resulting from human factors are identified there.
Selection of hazard-related scenarios for Summative Evaluation
All identified hazard-related scenarios will be selected for summative evaluation no matter the severity of the potential harm.
Documentation of the User Interface specification
According to the usability process, the user interface specification will be recorded among all the global software requirement specifications.
User interface evaluation plan
The R-TF-025-003 User Interface evaluation plan will be created and will document the methods and planning for the formative and summative evaluation of the device.
Design and Formative evaluation
The design of the device will be conducted following the software development process. The formative evaluation, on the other hand, will be defined in the R-TF-025-003 User Interface evaluation plan.
Summative evaluation
The summative evaluation will be defined and conducted according to the R-TF-025-003 User Interface evaluation plan and the R-TF-025-004 Summative evaluation protocol.
The results of the summative evaluation and conclusion on the device's safeness and effectiveness will be recorded in the R-TF-025-007 Summative evaluation report.
Signature meaning
The signatures for the approval process of this document can be found in the verified commits at the repository for the QMS. As a reference, the team members who are expected to participate in this document and their roles in the approval process, as defined in Annex I Responsibility Matrix of the GP-001, are:
- Author: Team members involved
- Reviewer: JD-003, JD-004
- Approver: JD-001