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From feedback to launch

The symbiotic relationship between manufacturers and users of power equipment can be described as a feedback loop – but how does it actually work? Tildy Bayar visited one company’s production facility to find out what’s involved in designing a new technology range based on customer feedback.

Alternators at Cummins Generator Technologies’ Stamford, UK plant

Credit: Cummins Generator Technologies

A product is only marketable if it addresses real industry needs – and the only way to know what those needs are is to talk to the people on the ground, in what could be described as a mutually beneficial feedback loop. Like power producers, manufacturers of power equipment must keep up with, and even anticipate, changing industry trends from stricter emissions standards to evolving fuel economics to geographical shifts.

One sector that is growing by any account is the standby power market for generator sets, and a key component of any genset is the alternator. At Cummins’ alternator business, Cummins Generator Technologies (here abbreviated as CGT), general manager Stephen Hopkins says one-third of his division’s $500 million annual revenue comes from sales to Cummins’ engine division, while the other two-thirds come from sales to other original equipment manufacturers (OEMs).

So what does the industry want in an alternator? In designing its newest range, the Stamford S0 and S1, CGT asked its customers – genset OEMs and standby power providers – for feedback on what could be improved. Decentralized Energy visited CGT’s production facility in Stamford, UK and spoke with the senior management team for an inside look at how customer feedback can inform the ways a product is conceived, designed and produced.

‘Surprising results’

The S0 and S1 are 4-pole alternators rated at 60 Hz for the North American market and 50 Hz for Europe. They are targeted at the 7.5 kVA to 62.5 kVA power range.

Alastair McQueen, director of new product introduction, supervised the S0/S1 range’s journey from conception to launch, a two-year process. He recalls that the process began with a brief to ‘develop a market-leading alternator that meets customer requirements for the global standby power market between 7.5 kVA and 62.5 kVA’, with the target market being genset manufacturers.

However, even this initial concept wasn’t as simple as it sounds. ‘Standby means different things in different parts of the world, and implies different use of the genset,’ McQueen notes. ‘In North America you keep it in the cellar in case there’s a hurricane; in India it’s used most of the day every day. In India, if there’s lots of rain the power stations run; if there isn’t enough rain they don’t run, and people rely on gensets much more.’ In a product designed for the global market, he added, the question is whether the genset is ‘running for 200 hours a year, 500 hours a year, 700…? Actually, it’s all of them.’

So for end users, and thus for genset manufacturers, reliability is key – both for machines that are used a lot and for those that need to start up fast after sitting idle for long amounts of time. McQueen notes that a survey of CGT’s global customer base in advance of designing the S0/S1 revealed reliability as the top priority, which came as a bit of a surprise to some. ‘The engineering department would have said efficiency would be top of the list,’ he says, ‘but it was sixth. Reliability was first.’

Kevan Simon, global technical and quality director, says the survey was crucial to the development process for a new product, which is ‘all about understanding which aspects are key for customers. Very often we think we’re the industry experts and go in with a preconceived idea of what the customer wants,’ he notes. ‘Very rarely do we use our ears and really listen to what they really want.’

Hopkins agrees that the survey results were slightly surprising. ‘I would have [the priorities] in a different order,’ he says. ‘Short lead times would be higher and efficiency would be higher.’ According to the survey, what genset manufacturers look for in an alternator is, in order of priority: reliability, low initial cost, service and responsiveness, durability, short lead times, and efficiency.

Passing the gates

The S0/S1 project was launched in 2014 with a 28-person dedicated programme team at CGT’s facility in Pune, India. McQueen says the firm chose this location because India is a key growth market for the alternator’s kVA range, and Simon notes that Pune is also home to Cummins’ new $184 million technology centre which, when it opens at the end of this year, will be the base for around one-third of Cummins’ engineers worldwide.

‘It makes a huge amount of sense to develop the product [in Pune],’ says Hopkins. ‘There is huge engineering expertise in India; there’s a domestic market there as well.’

Product development was based on a ‘gated’ process, a concept borrowed from the automotive industry, which involves demonstrating progress through a series of milestones. CGT’s process features seven such ‘gates’: start/layout of the full development plan, contract, presentation of a stable design, proving performance, proving durability, showing that the product is ready to go to launch, and closing the process down. ‘It’s an evidence-based process,’ Simon says. ‘It’s not just about moving from one position to another, but about showing how you did it.’

Scott Strudwick, global sales and marketing director, adds that the process is used to co-ordinate all departments involved with a new product: ‘IT systems, website, making sure the parts are in the right places at the right times – the process looks across all the different functions that need to be synched.’ McQueen notes that the firm’s senior leadership is ‘involved all the way through’ and sees monthly updates in addition to the gated reviews.

The S0/S1 alternator

Credit: Cummins Generator Technologies

Within the process, the firm does three different builds. The pre-alpha build demonstrates the product; the alpha phase demonstrates its performance – ‘We use that build to generate the majority of reliability hours,’ says McQueen – and the beta build shows quality and readiness for manufacturing. The subsequent testing features multiple stages. ‘We test the alternator in excess of 9000 hours in real-life applications; we put it in gensets, our own and in customers’ facilities, and test for 1500 cycles (around 1100 hours) to represent standby use and 1500 hours to represent prime continuous use,’ McQueen adds. The durability and reliability testing are ‘more extensive than you’d expect for a machine this size,’ says Simon, since the process has to validate it for both standby and prime continuous applications.

The process is also flexible, and each stage can be expanded if needed. ‘We realized during the process that we can learn and make improvements’ to it, McQueen notes. And Simon explains that ‘for this programme we did a second set of alpha builds because we weren’t happy that the first set gave us the performance level requirements we expected. So, we went into a design iteration loop and did some elements of redesign/re-verification.’

Hopkins says the gated process is ‘always iterative’. Typically, issues can arise when an initial business case does not produce, for example, the expected correlation between design and cost. If this is the case, ‘there is a commercial discussion and the design freezes’. If physical tests of the machine don’t give the same answers as the initial analysis, ‘then you go back to the analysis-led design, and then you do another test’. Because the gated process is based on timed milestones, Hopkins says many companies choose to adhere to a scheduled launch date even with missed deadlines in between, while CGT prefers to lengthen the process to achieve the desired result at each step. ‘If the whole programme should be 19 months,’ he says, ‘if you can’t get through [the second gate] do you lengthen the term of the project? If one gate takes six months longer, a lot of companies don’t change the launch date – we do.’

Automation at the Stamford plant

Credit: Cummins Generator Technologies

Optimizing production

Marvin Solowo-Coker, plant manager at the Stamford facility and former manager of Cummins’ plant in Lagos, notes that CGT has invested $11 million in efficiency improvements and capacity additions at the Stamford factory. The improvements have generated ‘massive savings in how we rationalize the footprint,’ he says. For example, all materials are now stored on-site or at a nearby leased site, ‘which leads to better material flow and more just-in-time flows, and reduces the materials we have on our line.’

Simon notes that the company is also gradually moving toward automation, with an overall plan for each plant that involves different levels of progress in different areas, depending on needs. In the firm’s Romanian factory, there has been ‘a huge investment’ in robotic coil taping, and another facility now features automated coil winding.

‘You don’t want to clear out the whole factory and spend $15 million on new automation lines’ if it isn’t necessary, Simon says. ‘You have to look at each facility: each needs different things.’

Solowo-Coker says value stream mapping is used on a yearly basis to re-examine all plant processes in terms of demand, efficiency, safety and quality. ‘Where there’s the opportunity to improve,’ he says, ‘that’s where we’d then invest in automation.’ He says the ideal scenario is one in which ‘you can bring the product in at a base level and then upfit that at a good cost’. Once a process is proven at a particular plant, he says, it can then be moved into factories worldwide.

According to McQueen, such a value quality assessment was used to optimize production for the S0/S1 range, resulting in a $2 million investment designed to improve capacity flows, throughput and inline verification checks.

From feedback to design

McQueen says that, for him, product development includes three categories: the ‘must-haves’ of compliance with codes and standards, a ‘more the better’ category including performance and quality, and a third category which he describes as ‘So what else can we offer?’.

In the case of the S0/S1, the part of the ‘what else’ that was based on customer feedback included a smaller size. ‘A lot of these machines get packaged into a genset or an enclosure system, which are really compact,’ explains Simon. For the S0/S1, a key requirement during the development process was to reduce the overall package footprint and spatial envelope relative to both CGT’s standard products and those of their competitors.

‘It was a key deliverable to work to the industry standard,’ McQueen says, but ‘in looking at industry standards relative to rotating equipment and the centre heights associated with those, we saw a whole range of different centre heights and foot positions.’ He says his team has reduced the centre height and improved the power density of the S0, with the shortest centre height standing at 132 mm.

Next, Simon notes, operators wanted reduced assembly times. ‘Matching to the generator, coupling with the engine around the SAE adaptor, getting access to the coupling discs – this can be quite complicated and hard for the operator because it’s quite a small machine,’ he says.

McQueen adds that ‘we have had direct feedback on that, speaking to the guys installing these on the lines’. Simon continues: ‘We changed our approach relative to the way we mount the alternator and how we then connect to the SAE, and then into the coupling disc. This improved operator access, and the window area has been increased by 20%-35% additional hand clearance. Because the SAE is flared, you can put your hand in really easily and uncouple the alternator to the engine flywheel very simply.’

Simon says CGT is looking into ways to further improve assembly time, including advanced casting techniques in the adaptor, which are ‘very non-standard for us’. To achieve weight reduction and improve ease of access, he says the firm aims to make sure ‘we only have strength in the casting where it’s absolutely needed’. To achieve this, stress and strain analysis was conducted.

In terms of improving durability, Simon says that ‘a lot of competitors out there today are using composite terminal boxes. We got a lot of feedback from customers saying “don’t go that way”.’ In addition to a sheet steel terminal box, the S0 and S1 models feature a separate AVR compartment which is shielded and electrically separated from the main connections and operator entry points. ‘From an electrical safety perspective, this is a lot safer,’ he says.

Another thing CGT’s customers wanted to do was easily replace another company’s alternator without re-engineering. The S0 and S1 are designed with flexible feet that bolt to the main foot, with a spacer option available that allows the operator to adjust the foot and inside foot plate drilling. ‘We looked at all of our competitors’ products and accommodated their mounting arrangements in our flexible foot, so you can lift up a competitor’s product and drop in this alternator without having to redesign,’ Simon says. ‘It can be bolted in and in situ within a couple of minutes.’

In marketing the S0/S1 range, CGT’s slogan is ‘You asked, we listened’. Through a variety of scenarios and feedback modes from surveys to collaborative testing, power equipment manufacturers are listening to their customers in order to respond together to the challenges of a changing industry.