Rapidly meeting customer requirements with simulation

Becoming a solution provider

The automotive industry global competition demands maximum mechanical engineering productivity. Schwäbische Werkzeugmaschinen (SW) GmbH’s multi-spindle machining centers efficiently manufacture precise components for vehicle powertrains, machine construction and precision engineering. Compared to four single-spindle machines, multi-spindle machines produce higher output with lower energy consumption and space requirements. SW achieved a group turnover of 471.8 million dollars in 2018 with around 1,000 employees worldwide. It took a consistent path from machine tool manufacturer to manufacturing systems solution provider. Jörg Schmauder, sales and market-ing managing director states: “We expand the potential for our customers with the interaction of all manufacturing operations in a low-maintenance operation with customized automation.” Schmauder continues, “This is why more and more companies are ordering complete manufacturing systems.”

In addition to subsidiaries in France, Italy, Poland, China, Mexico and the United States, an automation specialist in Tettnang, Germany was acquired in 2015. SW’s manufacturing systems carry out the core metal cutting processes, which include cleaning, drying, machining, assembling and leak testing, with low cycle times. The product-specific stations are interlinked and designed to customer specifications. This interaction decreases the operator’s personnel requirements and reduces error costs. At SW, the entrepreneurial risk increases with the customers’ goals and project size. They must agree to an output amount prior to production and follow through.

Initial simulation projects

In the bidding phase, cycle times and output quantities must align with the equipment offered. In competition, the equipment offer must be accurate in size as every saving impacts the target achievement and overall equipment effectiveness (OEE). “To submit accurate bids with a calculable entrepreneurial risk, we started initial simulation projects with the Technical University of Munich,” says Jochen Heinz, Industrial Data Services director at SW. “In 2017, we set up the simulation in-house.” Initially, SW chose to use Plant Simulation in the Tecnomatix® portfolio, which is a part of the Siemens Xcelerator business platform of software, hardware and services. “Tecnomatix Plant Simulation is number one by market penetration and requested by our automotive industry customers,” states Heinz. “We made our decision with regard to the entire Tecnomatix portfolio, which we successfully use today.”

SW also used Process Simulate in the Tecnomatix® portfolio for checking accessibility, collision risks and virtual com-missioning and NX™ Line Designer software for factory layout planning and production lines. “We needed a manufacturing-independent tool for the robots we use to standardize layout planning, even in the quotation phase,” explains Sven Makis, sales managing director at SW Automation.

Layout planning exclusively took place in the 2D environment until 2017. With automation module standardization, Line Designer and Process Simulate possibilities, quotation phase layout planning moved from 2D to 3D. “This offers us consistency, from the initial concept in Line Designer to Process Simulate reachability and cycle-time simulation,” says Makis. In addition, there are Teamcenter™ software installations for data management and NX computer-aided manufacturing (CAM) software for creating and checking network computer (NC) pro-grams. “We want to shape the company’s digitalization with Siemens,” explains Stefan Weber, production and technology managing director at SW.

On-premise simulation

Dr. Ayman Al Khateeb, senior consultant at SW, has driven the use of Plant Simulation since the beginning. Initially, scenarios were developed and simulated in 2D. The efficient production of aluminum, steel and titanium cylinder heads, transmission housings, battery housings for electric vehicles, impeller wheels for turbochargers and compressors for air-conditioning systems is validated in advance to achieve the customer’s specifications. “With simulation, we can meet high customer requirements cost-effectively,” states Dr. Khateeb. “If our automation experts are not convinced by a customer’s plant concept, we can clearly present the weak points in cycle times, bottlenecks and our development strategy.”

When existing lines need to be converted to new product variants or model series, customers commission feasibility studies and concept development as-a-service. This is also applied when higher output quantities are required. The smallest changes can have a big impact – one second less in cycle time can translate to thousands of more parts per year. “With a well-built simulation model, we achieve between five to 10 percent productivity gains,” explains Dr. Khateeb.

Digital twins

SW switched to 3D technology in 2019 to improve results and cope with growing complexity. Since then, Franciscus de Vries, consultant at SW, has been working on projects using Plant Simulation and Line Designer. To do this, extensive libraries of standard components were created and computer-aided design (CAD) data from the company’s design department and suppliers, such as robot providers, were transferred. A plant with ten machining centers was designed for an automotive supplier based in Bavaria, Germany. Robots transport the parts to a cleaning and leak-testing facility, remove them and place them on pallets. Four variants had to be machined on one or all of the machines. The control is carried out according to the push principle. “The order distribution, buffer design and gantry robot programming with single or double grippers was so complex that you could not solve the task without a 3D simulation model,” says de Vries. “We can precisely see which parameters we can achieve the desired results in with the digital twin.” This way, robot collisions on the gantries are ruled out. Due to the preliminary work, the pilot project took about ten months. “Today, our user library comprises of about 60 to 80 percent of the standardized system parts, which is why we estimate one month for projects,” says Heinz.

Virtual commissioning

The invested effort has already paid off with the savings made during commissioning. Previously, each plant was set up in the company’s factory, or in modules for larger plants.

“Virtual commissioning enables us to identify risks earlier and reduce commissioning time at the customer’s site. It is the key to being successful and cost-efficient in a market with rapid project lead times and growing demands for our systems’ availability,” explains Arne Graap, production and technology managing director at SW Automation.

Simulation enables SW to identify collisions early in the engineering phase and form the basic framework for the subsequent virtual commissioning of its plants, before they are built.

“The virtual commissioning of the plants saves us days to weeks of time and costs in the five-digit range,” states Heinz. “We have reduced our commissioning time by 30 percent, rapidly and efficiently met our customers’ requirements and reduced risk as a plant manufacturer with Siemens’ technology.”