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A Design Review is one of the most important checkpoints in any Product Development Process. When engineering, manufacturing, and quality teams sit down to evaluate a design before it moves forward, they have a rare opportunity to catch problems while changes are still cheap. A thorough Product Design Review can mean the difference between a smooth launch and a production line that grinds to a halt. The cost of finding design issues after tooling or production begins is dramatically higher than catching them during review. A flaw discovered on paper might cost a few hours of rework. The same flaw discovered after a mold has been cut, a fixture built, or a production batch run can cost tens of thousands of dollars and weeks of schedule slip. Effective reviews reduce redesign, delays, and manufacturing risk across the board. This article walks through the most common mistakes companies make during design reviews and how to avoid them, so your next Engineering Design Review catches the issues that matter before they reach the shop floor. Overview A Design Review brings cross-functional teams together to evaluate a product before it advances to tooling or production. Common mistakes, such as skipping early-stage reviews, ignoring tolerancing, or overlooking material availability, can delay production, raise engineering costs, and reduce product quality. Structured, cross-functional reviews that include manufacturing, quality, and supply chain input improve manufacturability and significantly reduce overall project risk. 1. Skipping or Rushing Early-Stage Design Reviews (PDR/CDR) The Preliminary Design Review (PDR) and Critical Design Review (CDR) are two of the most valuable checkpoints in the Product Development cycle, yet they are often rushed when schedules tighten. The Preliminary Design Review (PDR) confirms that the overall design approach is sound before detailed engineering work begins, while the Critical Design Review (CDR) verifies that the design is ready for release to manufacturing. Skipping or compressing these milestones makes it far harder to identify risks before design freeze. Once a design is frozen, the cost of late design changes rises sharply because tooling, fixtures, and supplier commitments are already in motion. Early stakeholder alignment during PDR and CDR keeps surprises from surfacing downstream, when they are far more expensive to fix. 2. No Cross-Functional Team Involvement A Mechanical Design Review that only includes engineers misses critical perspectives. The strongest reviews bring together Engineering, Manufacturing, Procurement, Quality Assurance, Supply Chain, and Service & Maintenance teams, each contributing a different lens on the same design. Manufacturing flags process limitations before they become production blockers. Procurement identifies sourcing constraints early in the cycle. Quality Assurance raises inspection and tolerance concerns front. Supply Chain flags lead-time and component risk. Service & Maintenance teams highlight long-term serviceability needs. The benefit of collaborative decision-making is that issues surface while they are still inexpensive to fix, rather than after commitments have already been made. 3. Poor Version Control and Engineering Change Management (ECM) When multiple versions of a drawing circulate without clear labeling, different teams end up working from different “truths.” Production might be machining to Rev C while procurement ordered materials against Rev B specs. This mismatch often isn’t caught until parts fail to fit or an inspector flags a discrepancy, by which point time and material are already lost. Engineering Change Orders (ECO) An ECO is the formal instruction to implement an approved change, whether it’s a dimension update, material substitution, or process revision. It typically documents what’s changing, why, who approved it, and the effective date. Without a proper ECO process, changes get made informally through emails or verbal instructions, which are easy to miss and impossible to audit later. Engineering Change Notices (ECN) While an ECO authorizes a change, an ECN communicates that a change has happened. It’s the notification that pushes updated information out to everyone affected, manufacturing, quality, purchasing, and suppliers, so no one is left working from stale data. Skipping this step is a common reason outdated drawings keep resurfacing even after a design has already been revised. Drawing management This covers how drawings are stored, labeled, and retrieved so the current revision is always easy to identify. Simple conventions, like consistent revision blocks, clear naming, and restricted edit access, prevent the everyday mix-ups that cause the biggest downstream headaches. PLM/PDM systems Product Lifecycle Management and Product Data Management systems give this process real teeth by centralizing files, enforcing revision control, and tracking approval history automatically. Rather than relying on individuals to remember which version is current, the system itself controls access and visibility, cutting down on human error significantly. Preventing outdated files from reaching production The final safeguard is making sure obsolete drawings simply cannot reach the shop floor. This means locking down superseded files, controlling who can release documents to production, and building checkpoints that verify the latest approved revision before work begins, so an old file never gets a chance to cause expensive rework Strong drawing management, supported by PLM/PDM systems, prevents outdated files from reaching production, which is one of the most preventable sources to avoid major conflicts   4. Overlooking Material Availability and Supplier Capabilities Material availability Even a flawless design can stall if material lead times aren’t considered during review. Long-lead items, single-source materials, or components facing global shortages can quietly derail a schedule if they’re only discovered after production release. Factoring availability into the review itself, rather than treating it as a purchasing problem to solve later, gives the team room to plan around delays or identify substitutes before they become urgent. Supplier capabilities A design that looks sound on paper can still run into trouble if it exceeds what a supplier can reliably produce. Understanding supplier manufacturing capabilities up front, including tolerances they can consistently hold and processes they’re actually equipped for, prevents mismatches between design intent and shop-floor reality. Building in alternative material or vendor options at the review stage also helps teams avoid surprises tied to component obsolescence or single-supplier dependency. Cost implications and broader supply chain risks should be discussed openly during the review rather than discovered after purchase orders have already been placed. 5. Treating Design Reviews as a Checklist Instead of