Defining the stages of design and reviewing every stage of the design process is one of the requirements of ISO 13485 Section 7.3.5 for design and development. The task of identifying and reviewing designs at every stage is accomplished using the design control SOP. Once the User Requirement and Specification (URS) for a medical device is established, the next step in the planning stage is the Design and Development Plan (DDP).
Every product has its unique design and development plan, and they appear in the products documentation as either DDP or D&DP. There are two main things to consider when creating a Design and Development Plan for a medical device.
- Draft the plan and approve it using the design control system.
- At crucial moments in the design stages, update and review the plan.
What is in the DDP
The Design and Development plan will differ with the complexity of each product as well as with the organization that produces them. For a simple product, the DDP can be in the form of a basic flow chart. However, with a more complex product, the design and Development plan will be in the form of a well-detailed Gantt chart.
The first thing that the DDP should cover is the objectives and goals for the product. This will help clarify the purpose of designing the product and its functions. Next, the DDP should note the various departments involved in the designing of the product and their roles. In addition to that, information on contractors or sub-contractors that will be contributing to the project. The assignment of responsibility as well as documenting them is vital to the success of the product design. Likewise, collaborations and shared responsibility should be elaborately defined to eliminate ambiguity or confusion. This is vital if the project involves multiple teams or departs.
The design and development plan should also have a breakdown of tasks alongside the people/team responsible for them. The task breakdown should include the following;
- The time duration for the product design.
- The resources that would make the project a success.
- Individual responsibility for set tasks.
- Allocation of resources.
- Criteria for fulfilling each task
- Collaboration points and the teams are collaborating on a specific task.
The task breakdown will help optimize the time it takes to complete the product and get it ready for the market. There should be a report documenting the target for each task, and it should have tests and studies that prove that the product is safe for use. Some of the tests and studies to consider are as follows;
- Shipping studies
- Biocompatibility testing
- Validation of sterilization processes
- Non-Clinical animal studies
- Electromagnetic Field (EMF) Interference studies
- Clinical evaluations
The tests and studies to be conducted will depend on the type of product design and the function of that product.
Another set of criteria that should be present in the design and development plan is what to expect from the activities of design transfer, and how to monitor what is being transferred. The expected result from the design process should also be weighed against the process input.
Problem with Design and Development plan
The biggest problem that comes with a DDP is the way the project manager tends to overestimate the product design timeline. Usually, such a problem arises with a lack of experience, lack of optimization and flexibility to the plan, and trying to work backward. It is important that tasks are completed on time, but there should be room for updates to account for unforeseen circumstances in the design process.