Prognostics: Manufacturing's Next Frontier

“The next frontier beyond measurement and monitoring is the idea and practice of prognostics,” says Arun Sinha, director of business development at Opto 22 (www.opto22.com), a Temecula, Calif.-based automation vendor.

C. Kenna AmosContributing Editor

May 1st, 2009

国家科学基金会（NSF）多元大学主任杰伊·李（Jay Lee）解释说，智能维护预后学的概念与预测维护相反，而不是预测维护的趋势，而不是预测性维护，这是数据的更多趋势。情报维护系统中心(CIMS,www.imscenter.net），在辛辛那提大学。

Moin Shaikh says prognostics represents an engineering discipline focused on predicting the future condition of a component and/or a system of components. “Prognostics is process- and device-centric, while predictive maintenance is only device-centric,” adds Shaikh, marketing manager with the Process Automation Systems Group, for vendorSiemens Energy & Automation Inc.(www.siemens.com），在宾夕法尼亚州的斯普林之家。

但是，您需要可操作的信息，强调了辛辛那提大学高级制造业的俄亥俄州著名学者Lee。“我们（在CIMS）使用智能软件或算法来转换数据。”他说，一个常见的现实世界例子是天气预报。预测数据可能是环境温度和风速，而预后信息可能是降雨或降雪的可能性。

Better knowledge

It’s through similar industrial forecasting that prognostics add value to end-users. “It reduces the cost of unscheduled maintenance, and, for that matter, also reduces scheduled maintenance due to having better knowledge about how long a mechanism will last,” says Ralph Maguire, principal engineer for the automation supplierBosch Rexroth Corp.(www.boschrexroth-us.com), Hoffman Estates, Ill. It optimizes productivity, and ultimately, the financial bottom line, by moving from a reaction-based maintenance mode to a proactive mode, Sinha notes. “It helps avoid unplanned downtime,” Shaikh says. “Prognostics shows how much savings occurred,” adds Lee.

To fulfill all those potentials, prognostics produces four types of actionable information, Lee explains. One is degradation. “That’s about performance change. It’s from 0 to 1, where O is not acceptable and 1 is the best.” The second type is minicomponent, each with its own degradation that’s shown in what is called a “radar chart.” These three-dimensional views allow end-users to see when components degrade, he explains.

The third type is pattern. It states, according to Lee, “multiple degradation into one combined symptom.” For example, a person goes to a medical doctor and complains of a parched throat. “The doctor will judge you, based on what you have,” Lee remarks. However, “if you have a fever, it might be flu. But if your nose is stuffy and sinuses stopped, you might have an allergy or cold.”

Risk is the fourth type of actionable information prognostics offers, Lee states. Using a risk chart, “this means that before degradation occurs, before you take action, you must know the impact.” Cost and criticality comprise impact, he explains, “and you take action based on the highest impact that could occur.” For example, if given a flickering light bulb vs. a malfunctioning air-conditioning (A/C) unit, you’ll likely check the A/C unit first, “because the downtime of a light bulb failure is less than the downtime of the A/C unit.” Lee notes that the cost component is the total downtime cost.

李强调，这些风险图表可以帮助人们计划。但是，为了提供最佳信息，他建议，需要在系统中的每个组件上完成图表。为此，NSF的CIMS开发了20种算法，Lee指出。使用它们，“一旦您对健康与成本有透明的看法，那么您就可以采用更好的方法来优化，策略和优先考虑维护。”这是回报。李说：“如果我们可以拥有与产品，质量，生产率，安全性以及供应商质量有关的以信息为中心的维护，那么维护的智能可能会影响更高的价值。”

C. Kenna Amos, ckamosjr@earthlink.net, is an自动化世界贡献编辑。