• Article published in Motion Control. Authour: Sammy Soetaert.

“Growing faster than the sector itself

BMT Aerospace fait partie du BMT Group, qui emploie 6.000 personnes dans le monde. Les racines de BMT se situent dans l’industrie du pignon, au sein de la firme Watteeuw. BMT a commencé à la fin des années 80 à produire des pièces notamment pour Airbus. Aujourd’hui, BMT Aerospace compte 3 filiales, réparties à Oostkamp, Fraser et la nouvelle usine en Roumanie. 110 personnes travaillent actuellement à Oostkamp. Comment l’avenir s’annonce-t-il pour le secteur aéronautique ? Koen Devolder exulte: “A chaque instant, il y a en moyenne 10.000 avions dans le ciel. Les modèles ‘single aisle’, c.-à-d. les avions à un seul couloir comme l’Airbus A320 et le Boeing 737, se taillent la part du lion. Rien que pour cet Airbus, 6.000 commandes sont actuellement ouvertes. A un rythme de production de 600 à 700 pièces par an, cela est donc bon pour quelques années. Notre objectif est de croître plus rapidement que la moyenne de l’industrie aéronautique. Un défi de taille.”

A propos de slats et de flaps

En montant dans n’importe quel avion de transport de passagers, vous avez une chance sur deux qu’une pièce provenant d’Oostkamp en Flandre occidentale vous assure un vol en toute sécurité. La gamme de pièces de l’entreprise est limitée en taille, mais pas en qualité: il s’agit de pièces importantes des ailes. La production de systèmes ‘rack & pinion’ complexes constitue l’activité principale de l’entreprise.

Koen Devolder, site general manager: “Un rack ordinaire est en fait une crémaillère droite, mais chez nous, cela est bien plus complexe. Notre produit est un secteur parfait d’un cercle, devant être fini avec une précision extrême.

Ces systèmes rack & pinion spécifiques sont utilisés au niveau des slats d’une aile d’avion de la plupart des avions commerciaux, comme l’Airbus A320. Les slats sont déployés sur la longueur de l’avant de l’aile. Ils donnent plus de portance au décollage et raccourcissent le temps d’atterrissage, car la vitesse par rapport au sol peut être plus réduite.”

“Chez BMT Aerospace, nous produisons des pièces pour un deuxième élément important: les flaps. Leur fonction est comparable à celle des slats – plus de portance au décollage et un temps d’atterrissage plus court – mais les flaps se trouvent à l’arrière de l’aile. Nous produisons ces assemblages pour l’Airbus A350. Nos entreprises soeurs produisent aussi d’autres pièces, comme des éléments de transmission pour hélicoptères et des pignons pour moteurs à réaction.”

Certification: a challenge in itself

In the spring of 2019, the topic of aircraft safety received extensive media coverage, in light of the software problems encountered by the Boeing 737 Max.

Nevertheless, aeroplanes are, and will remain, the safest form of transport. The risk of dying in a car accident is around 1,000 times higher than in a plane crash. This statistic is a reflection of the very strict certification process that exists in this sector.

Koen Devolder: “Under EASA (European Union Aviation Safety Agency) rules, everyone who wishes to deliver a finished product for use in the aerospace industry must be certified to this end and the production processes themselves must be certified by Nadcap. This certification, showing that a company’s processes meet aerospace industry standards, is granted only after strict audits have been performed. On average, we are audited on 23 days a year.”

“The requirements imposed on our parts are extremely stringent, and include: goods inward inspections, tensile tests, production measurements, hardness measurements, destructive testing, metallurgic structure inspection, inspection on grinding burn, MPI crack detection, CMM dimension checking, and lastly, final inspection. In most cases, 100% of our parts have to undergo these tests. In fact, it’s true to say that as much energy is devoted to testing as to the production process itself.”

VERTICAL INTEGRATION

What is special about BMT Aerospace is that the company deals with the whole production process, from raw material through to finished product. However, given the nature of the production process – involving precision machining and specific processes – this is a major challenge. Machining of rough cuts, heat treatment, copper plating, case-hardening, cold forming, phosphate coating and specialised testing activities are just some of the many processes carried out here.

Koen Devolder: “We start with the forging and end with a fully finished part. During this process, the part undergoes several very specific stages of machining, involving mechanical and chemical processing, as well as heat treatment. Consequently, developing our industrial plant is really a task for the experts. You won’t find much standard machinery here.”

Three transformations

For BMT Aerospace, the road to the Factory of the Future award began in early 2017.

Devolder: “We began by completing a self-calibration questionnaire. This identified a few points requiring action. During the next phase, we appointed a program manager. As our results for the ‘Digital Factory’ section could have been better, we also decided to recruit a digitalisation expert. We also visited a number of former prizewinners and attended a few sessions with Agoria. We also sought partners to assist us with our transformation. This taught us a great deal, but in the end, we went ahead with the task ourselves, without any help from consultants.”

“At the next stage, we submitted a roadmap to Agoria in late 2017, showing our projects in progress, plus some potential measures that we needed to evaluate. This was the basis for our work. We wanted the programme to make a genuine contribution to our company’s profitability. The idea was that Factory of the Future should be more than just a banner adorning the frontage of our site. We wanted the title to really have a positive influence on our activities. Our best scores were for the ‘world class production’, ‘networked factory’ and ‘digital factory’ transformation categories.”

Advanced Manufacturing Technologies

Transformation no. 1 concerned the production process: this is precisely where BMT Aerospace excels. Henk Vincke, Supply Chain Manager, comments on these adaptations: “We began by analysing changes unfolding in our business model. Customer are becoming more demanding, in terms of pricing and precision. So, the challenge lies in producing goods more cheaply, while at the same time reducing tolerances. In the case of some parts, these tolerances can be up to ten times tighter. We also noted that our product range was increasing in size, from around forty 40 lines ten years ago to 110 today, with more complex assemblies being added. Volumes are constantly rising. too.”

“For some time now, we’ve been using a ‘technology roadmap’ to compile a list of innovations that may be of interest to us. Last year, for the first time, we drew up a technology roadmap specifically tailored to Industry 4.0. This year, we also prepared a 3P workshop, in the context of which we performed a comprehensive analysis of our largest production line for A320 racks – which represent our largest volume – with a view to reorganising it. Two new concepts emerged from this, together with ten or so new techniques. We are now examining the feasibility of these techniques. Some are not yet available on the market, while others are, but have not yet been applied in the aerospace sector.”

“Some of our most impressive current production facilities are: the die quenching installation, the joint automated feed for four CNC machines, robotised shotpeening and an automated installation for chamfering, milling and demagnetisation. The introduction of vacuum furnaces and installation of the five-axis grinding machine, which can perform both grinding and milling operations, were also highlights. However, this work is ongoing. Investments have been made in camera measuring, automatic measurement of cutting tools, the turning/milling machine with a built-in washing machine, … Next year, we’ll be working on the pre-milling of racks and the transportation to the next process. We are also working on a number of new projects, such as research into new, easy-to-maintain rack & pinion concepts, grinding machine automation and developing our knowledge of techniques such as zinc/nickel and 3D printing. We are also testing materials such as titanium.”

“All of this represents a vast amount of work, but it will be worth it in the end. As a result, the number of hours worked per part has fallen, despite the growing complexity of these parts. There has also been a huge fall in the percentage of metal scrap we generate, from 3.5 to approx. 2% on average in 2018. Delivery reliability has risen spectacularly. Back in 2013 it was still 75%, compared to 99.5% in 2018.”

“What’s more, I’d like to emphasise that we have never lost sight of the people working for us at shopfloor level. For example, we introduced self-managing teams as part of this programme. This arrangement is working well and our operators are enthusiastic about it too, but you have to make sure this enthusiasm doesn’t slowly dwindle. This could happen for example whenever the same person always carries out the enjoyable tasks, and vice versa for the less pleasant tasks.”

Networked Factory

When we hear the term ‘production network’, we often think that this is about the ways in which companies and processes are digitally connected. In the Factories of the Future context however, it means something quite different: companies are evolving from solo actors into networked organisations. This means that risks and capital can be split between the various components making up a coherent network. An optimised ecosystem of suppliers and partners creates space for flexible cooperation agreements. Jan Peirs, BMT Aerospace R&D engineer, approves of this vision: “BMT isn’t an island. We form a network, together with several types of actors: the authorities, other companies, educational establishments, suppliers, customers, institutes specialising in knowledge, and others. If we look for example at the relationship with our suppliers, it goes much further than a straightforward purchaser/seller relationship. We work closely together on developing prototypes, we provide advice and we perform testing together. This situation is beneficial for both parties. As a customer, we have a special relationship, with access to their testing laboratory, their expertise and their solutions. The supplier, for its part, enjoys direct access to the application for which its items are used. This also applies to situations where we are the supplier. Thus we have regular Technology Alignment meetings with Airbus, and later in the month, we’re holding a technical workshop with Irkut.”

“We have various forms of collaboration with educational establishments, such as monitoring doctoral theses, internships and participation in on-the-job learning programmes. From time to time, this leads to someone being recruited. This too, is a situation that benefits all parties.”

“The authorities have some interesting options, e.g. for patents. Their price is much lower than that charged by private companies. We also use the i-Depot, where we can have ideas registered. This may be helpful on a legal level in the event of discussions around licences.”

“We are also collaborating with partner companies. They are neither customers nor suppliers, but they are active in the same sector as us. The advantage is that we can draw on our combined know-how. This makes you stronger, so that you can achieve more, with fewer resources of your own. However, this approach calls for a certain level of commitment, as you yourself have to demonstrate a certain openness.”

“Lastly, I would also like to draw attention to research institutes, such as universities, Sirris and Flanders Make. For the moment, we don’t have any 1-to-1 projects in progress, but we are monitoring several research projects via user groups. That way, we stay in touch with the results achieved.”

Digital Factory

Digitalisation is everywhere. As a company, you need to keep up with the changes taking place in this field. For BMT Aerospace too, this constitutes a serious challenge. The firm felt that it needed to do something about this, so it recruited a digitalisation expert in the person of Stefan Savat.

He is guiding us through what needs to be done and the specific challenges facing the company: “We ourselves have developed Jobcontrol, a system whereby operators are in possession of the right information at all times, using PLM engineering software in particular. The feedback they provide is vital, as we sometimes forget that this is a prerequisite for measuring OEE (Overall Equipment Effectiveness). Obtaining data fed back by machinery is one thing, but we always need feedback from shopfloor level.”

“We perform a vast number of specialised and/or automated measurements on our parts. Traceability is vital, too. Our customers are requiring us to provide growing volumes of process-related data. The ‘digital passport’ belonging to every single part is therefore of growing importance. Managing all of these data flows was a huge challenge. My colleagues and I therefore centralised all this data during the most recent period. This involves extracting it from Excel, PDF and CSV files. We keep this information combined at local level, not in the cloud. The advantage of this centralised approach is that you can then access all of the data directly on each workstation. But to make sure we were really looking at an Industry 4.0 application, we then added an extra layer. Up to that point, the data took the form of a snapshot. Now however, data is generated every fraction of a second. This means we really have ‘megadata’, which we can use to identify specific trends. Here too, feedback from operators is essential. Incidentally, they themselves are eager to see some of these displays. They want to be the first ones to spot any errors.”

Conclusion

What were the main challenges facing BMT when it wanted to become a Factory of the Future?

Koen Devolder: “We wanted a good business case for each project. We envisaged a whole series of fine projects, but many of them didn’t come to fruition, because the return on them was too low. We are lucky in that our shareholder is totally committed to innovation and wants to turn Oostkamp into a technological trailblazer. We have enjoyed unconditional support from our management and our shareholder for the ‘Factory of the Future’ programme.”