In an unexpected move this morning, 3D Systems (NYSE:DDD) warned investors that its third-quarter earnings will come in lighter than expected and its 2014 full-year guidance has been trimmed. Shares opened down more than 16% and printed a fresh 52-week low shortly thereafter.

For the quarter, 3D Systems expects to generate revenue between $164 million and $169 million, earning between $0.16 and $0.19 per share on an adjusted basis, or $0.01 and $0.03 per share on a nonadjusted basis. Analysts were expecting 3D Systems to generate $186 million in revenue and take home $0.26 in adjusted earnings per share. A year ago, 3D Systems' third-quarter revenue rang in at $135.7 million, translating to $0.26 per share in adjusted earnings -- implying that 3D Systems expects to grow revenue between 21% and 25% this year, which compares unfavorably to the more than 31% the 3D printing industry is expected to grow this year.

Additionally, 3D Systems lowered its full-year revenue guidance from between $700 million and $740 million to between $650 million and $690 million -- well below the analyst consensus of $707.6 million. This may have come as a surprise to investors because 3D Systems slightly raised its full-year guidance last quarter.

The heart of the disappointment
3D Systems' roughly $20 million quarterly revenue shortfall relative to expectations is centered around two execution issues. First, 3D Systems' deliberate decision to delay the shipment of some of its upcoming consumer-oriented 3D printers is pushing revenue recognition of these products into future quarters. Second, 3D Systems is experiencing manufacturing constraints because it's fallen behind on bringing additional manufacturing capacity online for its direct metal 3D printers -- which was initially expected to be up and running in the third quarter. 3D Systems highlighted last quarter that demand for its metal 3D printers continues to outstrip manufacturing capacity.

During today's preliminary earnings call, management highlighted that it views these execution issues as a temporary speed bump and believes the underlying long-term fundamentals of its business remain intact. Judging by the $10.1 million sequential increase in its order backlog to $42 million, it does appear that these issues are execution-related and not demand-related. If this working theory holds true, then 3D Systems should be able to correct these execution issues in future quarters and its earnings results should reflect these improvements.

Still, today marks three consecutive earnings misses in a row, and investors may soon begin to question -- if they haven't already -- the operational risks associated with 3D Systems' strategy of acquiring lots of businesses to fuel its growth. Perhaps 3D Systems' approach is overly aggressive, has too many moving parts, and is diverting management's focus away from operational efficiency.

New questions raised
Although investors don't have the complete picture of 3D Systems' third-quarter earnings, this warning has to make one wonder if the company will actually be able deliver on its promise of longer-term earnings growth, or if it will continue to find additional reasons that it cannot execute correctly. If execution issues persist, it'll become increasingly clear that management doesn't have a solid handle on its operations -- a revelation that likely wouldn't bode well for shareholders. However, without the complete picture of 3D Systems' third-quarter earnings, which are due out on Nov. 10, I think it's a little premature to take action and that investors should wait to see what the full story has to offer.

Steve Heller owns shares of 3D Systems and Apple. The Motley Fool recommends and owns shares of 3D Systems and Apple. Try any of our Foolish newsletter services free for 30 days. We Fools may not all hold the same opinions, but we all believe that considering a diverse range of insights makes us better investors. The Motley Fool has a disclosure policy.