Design analysis software helps engineers score 40 percent total savings on slot machine part and assembly costs.

Long before the lights start flickering in the video slot machine corner of a casino, a light bulb has to go on over a design engineer’s head.

And over the heads of an electrical engineer, a mechanical engineer, and a manufacturing engineer as well. “The simple part of a gaming machine is putting in your money and pushing a button,” says Sam Mikhail, Engineering Manager at International Game Technology (IGT). “The difficult part is keeping every other task relating to the machine nearly as simple. Our customers aren’t only the brand-name operators—it’s everyone who touches the machine.” That includes installation personnel, casino employees reloading the cash system, service technicians, players, and others.

Specifications for the gaming system are rigorous inside and out. Because it is an electromechanical product, there are EMF and ESD requirements as well as safety standards to meet. Beyond these, there are security requirements imposed for gaming equipment. “Safety, security, quality, functionality and cost reduction are our main design goals,” Mikhail says. In addition, the slot machines must be customizable for a wide variety of games, with new ones coming out every few months.

But the more complex the internal assembly, the more time-consuming assembly and service can be. Unless the design team strives for simplicity, their product can build in costs up front. That can raise IGT’s manufacturing costs—and the customer’s service costs as well. “Bear in mind,” Mikhail says, “Every moment that these machines are shut down they make no money for the casino. Ease of service is extremely important so, for designers here, that’s a constant challenge.”

To meet that challenge, and coupled with his experience in implementing Design for Manufacture and Assembly (DFMA) programs in a number of companies, Mikhail led the initiative to implement DFMA in IGT, turning to analysis software from Boothroyd Dewhurst,

Inc. (Wakefield, RI) as an integral requirement that complemented the workshops that emphasized DFMA principles and techniques.

Through the use of the software, one of the design teams in the pilot workshop managed to pare 30 percent off part cost and an impressive 50 percent off assembly times and costs for a critical electrical box used in many of their machines.

Inside the slot machine cabinet is a large array of electronic and mechanical components that perform the behind-the-scenes work for the games: generating random numbers for virtual reels, controlling the sights and sounds that make play entertaining, and managing and tracking payment in and out. “It’s very busy inside our machines,” Mikhail explains. “As a result, it’s also very crowded.” Numerous fasteners and limited access points can make assembly and service challenging and time-consuming.

For instance, the electrical box mentioned earlier originally contained two PCBs and a number of hard (plug) connectors wired to it and distributed around the box. The sheet metal box itself had multiple mounting points for parts and several electrical ground points  where studs had to be attached by hand and ground wires hooked up. Because there were so many parts in a small space, access was tight and assembly operations difficult. “That box was an obvious place to start a redesign,” Mikhail recalls. “In terms of its complexity and our ability to rapidly put a new design in production, it was low-hanging fruit.”

Before the redesign, Mikhail and other IGT personnel began training on their newly acquired DFMA software, which combines two complementary, closely integrated analysis tools: Design for Assembly (DFA) and Design for Manufacture (DFM).

DFA software enables engineers to reduce a product’s complexity by consolidating parts into elegant and multifunctional designs that provide significant cost savings. DFM guides designers through the selection of materials and processes. Early in product development, at the concept stage, the software helps engineers starting with basic shapes or CAD models to cost out alternative materials and processes. The extensive process library and cost models in DFM Concurrent Costing help to identify major cost drivers such as machining time, part handling (set-up) time, materials outlay, or secondary manufacturing processes such as finishing surfaces.