Over the past two years, Control Engineering has conducted reader surveys to determine user satisfaction with the principal product categories covered by the publication. To make these surveys more manageable, we split the total 29 product categories into two studies (16 categories in the first survey, 13 in the second) to be conducted in consecutive years and then repeated. As a result, this year's survey revisits the same categories first addressed in the 2004 survey publication (March 2004). The 2004 survey was conducted in fall 2003, and this year's survey in fall 2005.

Over 1,300 Control Engineering readers—all of whom purchase products across all categories covered—participated in this year's survey. Categories with the largest response rates were PLCs (644 respondents ranked products in this category), sensors and/or transmitters (324 respondents ranked products), operator interface hardware and software (ranked by 257 respondents), and I/O products and systems (ranked by 236 respondents). Categories attracting the fewest respondents were valve positioners (44 respondents), process analysis and loop-tuning software (24 respondents), and solid-state motor starters (23 respondents).

Respondents were fairly evenly distributed across the manufacturing and non-manufacturing sectors covered by Control Engineering. The biggest concentrations of manufacturing respondents work in industries defined as producers of industrial, commercial, agricultural, and other machinery or as producers of instrumentation, measurement, control systems, and related devices. In non-manufacturing industries, the largest group of respondents are employed in system integration and engineering.

Not surprisingly, most changes between the 2004 and 2006 survey are small—statistically insignificant. But even with such a short time span, some shifts were noticeable. Out of all the satisfaction areas covered by the survey, two areas that saw the biggest shifts were "repair" and "technical support."

Shifts in repair satisfaction were most significant in ac motors, block valves, distributed control systems (DCSs), and PLCs. Shifts greater than 5% were considered worthy of notation. With this in mind, only one category—ac motors—saw an improvement in repair satisfaction since the 2004 survey.

Following are percentages of respondents indicating "very satisfied" or "somewhat satisfied" with their repair experiences in the 2004 and 2006 surveys:

Despite decrease in repair satisfaction in three of the four categories with shifts of any significance, the fact that most categories shifted less than 5% indicate that since conducting the first survey, repair satisfaction in survey categories covered remain largely unchanged.

In contrast to the lower repair ratings in three of the four categories listed above, users indicate they are increasingly more satisfied with vendors' technical support. PC-based control software, process analysis software, and valve positioner buyers reported greater levels of technical support satisfaction in 2006 than they did in 2004.

Following are percentages of respondents indicating "very satisfied" or "somewhat satisfied" with their technical support experiences in the 2004 and 2006 surveys:

Having only one of the six categories with significant shifts report decreased satisfaction since the last survey indicates that vendors are getting the message about the importance of good technical support. Cost savings and better customer relationships are surely key to this shift.

End-user demand for this service must also be a driver for vendors' improved technical support. According to the survey, 47% of respondents, on average, required technical support for products in the categories covered by this survey. Of all the services examined in this survey, technical support ranked highest in terms of need, followed by software upgrades/bug fixes at 22%, hardware repair at 18%, and recalibration at 3%.

Products requiring the least amount of technical support are: ac motors and block valves and actuators, with 25% and 26% of respondents, respectively, reporting a need for this service. However, tech support was requested at significantly higher rates for DCS (75%), operator interface hardware and software (60%), ac adjustable-speed drives (57%), and process analysis and loop-tuning software (56%).

On the surface, it can be assumed that systems requiring higher levels of tech support are more complex, largely software-based systems. Or, could the need for higher levels of services in these areas be generated by the presence of fewer skilled engineers populating the manufacturing environment?

Though the survey examines specific satisfaction across 40 different areas, four areas stand out as key drivers across the board: price/value for the dollar, product performance, legacy product support, and quality of documentation/accuracy of Web site material.

Respondents ranked ac motors and block valves and actuators as the products with the best price satisfaction (86% each), followed by photoelectric and proximity sensors (84%), and sensors and/or transmitters (83%). Products with the lowest price satisfaction are DCS (43%), solid-state motor starters (35%), and PLCs and operator interface hardware and software (30% each).

Unsurprisingly, value-for-the-dollar rankings closely mirrored price rankings. The only differences are that PLCs did not rank as low in value for the dollar as they did in price, and valve positioners and control valves and actuators tied for second place in value for the dollar with a 90% positive response.

In the all-important category of product performance, top performers are: ac motors and control valves and actuators (97%); block valves and actuators, photoelectric and proximity sensors, PLCs and sensors and/or transmitters came in second with 95% positive response, followed closely by I/O products and systems at 94%. The bottom performers are: vision system software and hardware with 16% satisfaction; followed by solid-state motor starters at 12%; and DCS, operator interface hardware and software, and process analysis and loop-tuning software at 11%.

With so many devices installed throughout manufacturing—an industry not inclined to regularly upgrade plant-floor systems every few years—a vendor's commitment to legacy product support can be critically important. Top performers in this category are: photoelectric proximity sensors (95%); sensors and/or transmitters and control valves and actuators (91% each); and ac motors (90%). Products with the lowest legacy support satisfaction are DCS (23%), motion controller and/or positioners (22%), and PC-based control software (19%).

Considering that tech support is used so often—and has apparently become a center of expertise for many vendors—it's reasonable to expect that these same vendors would put a great deal of effort into product documentation quality and resources available on their Web site to serve as a resource of first resort before calling tech support. Fortunately, this does seem to be the case playing out in the market.

In terms of "quality of documentation," only one product category—solid-state motor starters—received a double-digit percentage (12%) of respondents claiming to be dissatisfied. Categories doing the best job of satisfying users in this category are: control valves and actuators, photoelectric and proximity sensors, and process analysis and loop- tuning software (all receiving a 94% satisfied response rate); valve positioners (92%); and sensors and/or transmitters (91%).

The only product category receiving a double-digit dissatisfied response (20%) is solid-state motor starters for the "completeness and accuracy of Web site material" category. The top performers in delivering satisfaction in this area are: block valves and actuators (100%), photoelectric and proximity sensors (92%), and valve positioners (91%).

Per survey results, PLCs ranked highest overall with a weighted score of 33,565, followed by ac adjustable drives at 18,704, and sensors and/or transmitters at 14,849. Valve positioners received the lowest overall satisfaction response at 1,967. Vision system hardware and software and motion controller and/or positioners fared slightly better at 3,749 and 5,835, respectively.

Based on examination of key areas, it would be easy to believe that software systems would suffer the lowest overall satisfaction ratings. But results do not bear that out: only one of the product categories among the bottom three is held by a software product. And in this case—vision software—the product was grouped with its hardware counterpart, making it difficult to determine whether the vision software or hardware was the primary source of dissatisfaction.

The two pure software products—process analysis and loop-tuning software and PC-based control software—did well with respondents when asked: "Based on your experience with the manufacturer's product, how likely are you to purchase from them again in the next 12 months?" Process analysis received a 94% positive response and PC-based software received a 93% positive response. Even the DCS product category—which is largely software-based—received an 87% positive response. The top most-likely-to-purchase-again winners are: ac motors (98%); I/O products and systems, photoelectric and proximity sensors, and valve positioners at 97% each; and control valves and actuators (96%).

Only one product category—process analysis and loop-tuning software—received a 100% satisfied response to the question: "Considering everything, not just the most recent interaction, how satisfied are you with the manufacturer's product?" Valve positioners came in a close second with a 98% positive response, followed by ac motors, block valves and actuators, photoelectric and proximity sensors, and sensors and/or transmitters at 97%.

All in all, users seem to be quite satisfied with the products covered in this survey. When examining all responses to the "considering everything" question, the lowest positive response was received by DCS and motion controller and/or positioner product categories, which both came in at a very respectable 88%.