Software helps engineers cut costs early in the design process

So-called 'lite' simulation software tools are increasingly being used by engineers at the front end of the design process is increasingly being leveraged by engineers. Being able to recognise at the conceptual stage fundamental areas of optimisation has proved valuable.

Running FEA or CFD early on by no means provides the same sort of in-depth analysis offered by specialists later on in the process. Rather the process points engineers in the right direction, letting them know when they are heading down blind alleys. This concept of early 'lite' analysis that can be run by more generalist design engineers was taken onboard by US-based aPriori. It wanted to provide the same sort functionality with costing elements within a design. "There are all kinds of ramifications of not having visibility to cost early in the product development cycle," says Rick Burke, vice president for marketing at aPriori. "You are making decisions about designs, materials, and manufacture without knowing how much anything will really cost. "Engineers have always been exceptionally good at meeting the form, fit and function requirements of a product. And while they might have some ballpark idea of how much it might cost, you can't just design a product and throw it over the wall to manufacturing and expect them to sort out getting the costs down. You just can't do that anymore... We have found a lot companies are increasingly looking for some type of solution to help them get early and accurate visibility to cost." Costing is generally done after products have been designed and passed to manufacture. Products can then enter into substantial redesign and development work to reduce product costs, which can be done after products are being manufactured and sold. Thisn is why many staggering cost reductions are possible several years after the initial product release. This proved a problem for US agricultural company John Deere, which prompted collaboration with a local university to develop software that was easy to use, compatible with modern CAD packages and, above all, able to inform engineers at the conceptual stage about cost. "The aim was to take a CAD model, extract all of its design features, figure out what each step in the manufacturing process would cost and then add them all up," says Burke. "We also needed it to be extremely fast and easy to use." Ten years on from that initial work with John Deere and aPriori has been able to expand beyond agriculture and construction equipment, and is now used by a broad array of industries including automotive and aerospace. The process is able to evaluate various processes accurately, including sheetmetal forming, plastic injection moulding, forging, castings, machining, heat treatment, as well as factory, assembly and labour costs. Cost avoidance The software from aPriori can be used across organisations by designers, sourcing, purchasing and for making outsourcing decisions. However, one of its greatest assets is the information it can give to a designer early on, not least by allowing them to set up target costs for a part or assembly. It is run in conjunction with a CAD model in real time and shows the effects new features or different materials has on the part cost. This is being dubbed 'cost avoidance' and is allowing engineers to get instant feedback on the effect what they are they designing has on the cost of a part to be manufactured and shipped. "With aPriori on the desktop, engineers can look at more design alternatives as they can instantly tell the difference in cost," says Burke. "We find users discover designs that meet form, fit and functional requirements, but prove to be lower in cost." This is similar to the philosophy of design for manufacture, which takes the view that designing a part for a manufacturing process will yield a lower-cost part, remove unnecessary processes and allow higher throughput. However, aPriori is quantifying this approach and showing the results in dollars and cents. For operations such as castings, for example, aPriori has been able to highlight the areas that are most sensitive to cost using a simple heat map laid over the model. This considers both the cycle time of an individual operation as well as any post operations. For example, if an engine block has a round along its circumference that has to be machined in, it may take 45 minutes to machine and cost £30. The software then analyses the design and shows heat map of the casting of everything that is exceeds a certain cost or cycle time in red. It then grades down to orange, yellow and eventually blue for features below the target threshold. The company has been able to make inroads to Europe over the past two years and has recently seen Iveco sign up as a user. The truck manufacturer is in the early stages of deploying aPriori and has a number of design and sourcing engineers currently using and configuring it. "Like a PLM system, it can't just be turned on," says Burke. "It is an enterprise application and takes time to set up. And engineers have not had the capability to calculate and manage cost to a target before, so that also takes time to work in to a process." The software works by importing the bill of materials from either a PLM or ERP system, which can then be organised in to different functional groups. Using the example of Iveco and truck manufacture, it may be powertrain, suspension, interior and so on. PLM data normally includes the part name, quantity and also an associated cost or budget, aPriori is then able to cost new designs that can be compared to existing designs to see the change. "The first process is extracting geometric cost drivers from the CAD model," says Burke. "We then have to build within the software 'virtual production environments' (VPEs). Like a real manufacturing factory where you have machines, raw materials, finishing, labour, electricity, light, heat and so on. We take everything: all these various elements and capture them in the software." There are nine starter factories that act as templates for customers to create their very own accurate and bespoke VPE. The starter factories represent different geographies around the world such Brazil, China, Eastern Europe, USA, and Europe, and vary labour and overhead costs appropriately, though these can later be adjusted to reflect the exact values of a given factory. Companies then add material costs as buying power varies greatly depending on the company size, and up-to-date real costs to make the system representative. Not just a design tool As well as being useful for designers to get a handle on cost early on, the software can be used elsewhere in a company to help quicker strategic decisions to be made. "If you need to make a decision on whether to make or buy a component, you can take the 3D model and run it through aPriori," says Burke. "You might see it costs £45 to make in the UK factory and £25 by a supplier in Brazil. Then it will factor in transportation and logistics and you can compare the 'landed cost' of site A vs. B. That allows you to make quick and accurate strategic decisions about what to make in house or what to buy from a supplier." The limitation on the software at the moment is complexity. Processes such as composite production are not yet available as standard. However, the company says it is in a state of evolution and continues to develop new cost models. "We have got the easy ones out the ways and are now working on the harder ones," says Burke. "Investment casting and composites are both on our road map."