Design for Test (DFT) is a critical part of product development that often determines how efficiently and accurately a product can be tested later in its lifecycle. At Circuit Check, we’ve seen firsthand how incorporating DFT early in the design phase helps teams save time, reduce costs, and ensure product quality before full-scale production begins.

What Is Design for Test?

Design for Test (DFT) is the process of evaluating a printed circuit board assembly (PCBA) to ensure it can be thoroughly tested during manufacturing. Using software tools to analyze CAD data, engineers can simulate how a board’s circuitry and connections will behave and generate reports detailing test access across the design.

Ideally, this process confirms that a PCB design offers optimal test access — but in many cases, it reveals opportunities for improvement. When issues are identified early, design teams can adjust their layouts or perform a board re-spin to improve coverage and simplify future testing.

Why DFT Matters More Than Ever

Testing modern PCBAs is becoming increasingly complex due to factors such as:

• Higher component and connection density

• Faster device speeds

• New surface-mount technology (SMT) processes

• Evolving materials and tighter board requirements

Neglecting to include DFT considerations early in the design process can lead to limited test access, longer debug times, and costly rework once the board is already in production. A well-planned DFT strategy helps engineers avoid these challenges, improving both yield and reliability.

What a DFT Report Reveals

DFT reports provide detailed insight into a PCB’s testability, including:

• The number of nets that can be tested (both multi-pin and single-pin)

• The size and placement of test pads on each layer

• Total quantity of test points across the board

• Potential layout or schematic changes to improve access

• Clearance issues between components, test points, and soldermask

• Recommendations for adding test points to increase coverage

This information gives design teams a clear roadmap to optimize their PCB layout before final builds begin.

Why Early DFT Pays Off

Running DFT analysis during preliminary design offers major benefits compared to waiting until the final version:

• Identifies design flaws that could affect structural integrity

• Highlights test access limitations before production

• Enables earlier and more cost-effective design adjustments

• Reduces risk of rework or scrap during manufacturing

Catching potential testability issues early means fewer production surprises and lower costs when the board moves to volume builds.

The Cost of Skipping DFT

Let’s look at an example that highlights why even a small amount of untested circuitry can have a major financial impact.

Company A is producing a new PCB assembly (PCBA) for its next-generation product.

The fully assembled product costs $900 per unit, so building 2,000 units per month adds up to $1.8 million in product costs each month.

If just 1% of those assemblies fail due to undetected PCB issues, the fallout costs are:
$1,800,000 × 1% = $18,000 per month, or $216,000 per year.

But the impact doesn’t stop there. If the product sells for $1,450 per unit, that same 1% fallout also results in $29,000 in lost monthly revenue, or $348,000 annually.

Over time, that adds up to more than half a million dollars in lost value — all from test coverage issues that could have been identified earlier with DFT.

The Real Value of DFT

Every percentage point of improved test access helps reduce fallout and rework, saving both time and money. Effective DFT implementation can:

• Minimize scrap and product recall risks

• Reduce troubleshooting and debug time

• Improve throughput and first-pass yield

• Support consistent quality and brand reputation

DFT isn’t just a quality step — it’s a smart business decision.

Partnering with Circuit Check for DFT Success

At Circuit Check, we help OEMs and manufacturers integrate DFT best practices into their product development and test strategies. Our engineers leverage advanced software tools, decades of test experience, and deep design insight to ensure your PCBAs are optimized for efficient, accurate testing.

From in-circuit and functional test systems to complete turnkey solutions, we design for quality, reliability, and repeatability — right from the start.

Design for Test isn’t just about better boards — it’s about better business outcomes.
Partner with Circuit Check to build testability into your design from day one.