Edition #9 - The Importance of the Design Brief as a Foundational Document

The Product Design Brief (or Product Scope), is a critical document for reducing product risks during the product development phase. This document accompanies the concept throughout development and is referenced and updated as the project progresses. Each business typically develops its own template for this document, containing targets and outcomes relevant to their specific products.

Let’s explore why this document is so important for managing product risks:

The Product Design Brief serves as a single source of truth for product targets, helping to avoid discrepancies across different documents. The details captured in this brief will be used:

• by designers and engineers during product development
• as input to creating the product verification plan
• to guide the product risk assessment
• to determine applicable regulatory requirements and standards
• by the marketing team to develop marketing materials, labelling, user instructions, and packaging
  

The teams involved in these activities are typically involved in developing the design brief from the outset.
Below is a list of sections commonly found within a Product Design Brief.

1. Product Description: A high-level description of what the product is and does from the consumer’s perspective, setting a clear, shared vision early.
2. Functionality & Performance Targets: A detailed list of what the product must do, including measurable expectations that shape design and testing.
3. Unique Selling Features: Non-negotiable features that differentiate the product and are critical for market positioning.
4. Target User(s): Definition of the intended user group(s), enabling user-centred design and meeting compliance obligations.
5. Use Environment: Expected exposure conditions (e.g., heat, salt, chemicals), guiding durability and verification efforts.
6. Target Markets: Countries or regions of sale, which determine regulatory and customer expectations.
7. Product Type & Category: Classification of the product, which determines applicable standards and regulatory pathways.
8. Size, Weight & Packaging: Target dimensions and weight, including packaged form, influencing usability, logistics, and costs.
9. Loading Requirements: Expected mechanical loads the product must withstand, guiding strength and durability design.
10. Cost Target: Planned production cost, informing choices around materials, processes, and design scope.
11. Materials & Components (Known): Any predetermined materials or parts known from the outset, shaping sourcing and design decisions.
12. Configurations & Accessories: Expected product states (e.g., folded/unfolded) and accessories, ensuring complete system design.
13. Use Scenarios: Likely and edge-case handling or usage conditions, informing safety and robustness.
14. Actuation & Force Requirements: Methods and effort required to operate the product, shaping usability and safety features.
15. Maintenance & Repairability: Expected maintenance tasks or repairs, driving decisions around access and safety.
16. Life Expectancy: Target operational lifespan, informing durability design and warranty planning.
17. End-of-Life Disposal: Plans for disassembly, recycling, or safe disposal, promoting sustainable design and compliance.
18. Applicable Regulations & Standards: Relevant legal and technical requirements across markets, shaping early design decisions.
19. Market Variations: Known differences in regulations, expectations, or product variants across markets, supporting efficient planning.
    

Some of these elements will be included in the design brief from the outset, while others will emerge as the concept evolves. It’s also highly beneficial to explain the reasoning behind each requirement. For example, are the size targets driven by airline carry-on luggage restrictions? Is the weight target influenced by the offerings of competing products at similar price points?

As the concept progresses, trade-offs and concessions may need to be made. Having the rationale for each requirement ensures that decisions can be made with the best possible understanding.

When the importance of a product design brief is underestimated, or when it's hastily created and never revisited, various risks can arise. One common issue is when configurations, accessories, and the possible combinations of both are not considered. For example, if you have more than two configurations and any accessories, it’s crucial to map out the possible combinations in a matrix. This helps identify which combinations are feasible and which are not.

Updating the design brief as the concept evolves is just as critical as its initial detailing. For instance, if it’s determined that the weight target cannot be met, it’s essential to revisit the design brief, assess the implications of this change, and agree on a new target. This process helps prevent scope creep, which poses a significant risk to product development outcomes and timelines.

Over time, small decisions can accumulate, subtly shifting the concept further away from the original targets. Ultimately, this can result in a product that no longer aligns with the initial objectives, potentially rendering it unsellable. Any changes to the design brief should be agreed upon by the individuals responsible for defining it in the first place, as they understand the rationale behind the original requirements.

The product design brief serves as the foundation for successful product development. It sets clear expectations, aligns the team, and provides a roadmap to follow as the product moves through its lifecycle. By ensuring that the brief is comprehensive, regularly updated, and aligned with the product's evolving needs, businesses can minimise risks, prevent costly mistakes, and improve the chances of bringing a product to market that meets both customer expectations and regulatory requirements. The importance of a well-detailed and flexible product design brief cannot be overstated, as it guides decision-making, ensures consistency, and ultimately helps create a product that is both functional and viable.