Using Off-Site Spare Part Stocks to Maintain Systems
Companies that rely on assets to run their business often need to maintain stocks of spare parts. Where to set up these stocks, how many parts to keep in them and how often to restock them is a logistics question that affects the ability of the company to fix failures and maintain their systems. It is difficult to strike a balance between carrying enough parts to meet the company's needs and containing the costs involved in sustaining such stocks. A blend of on-site and off-site spare part stocks can be a cost-effective strategy. This article explains how to set up and use a combination of on-site and off-site spare part stock profiles when analyzing your systems using BlockSim 7.

Expanded Models for Accelerated Life Test Analysis with Time-Varying Stresses
Some accelerated life tests may use a time-varying stress application (such as step-stress or ramp-stress) to assure the observation of failures more quickly in order to shorten the product development cycle. Likewise, some products are expected to be operated under normal use conditions where the stress exposure varies with time. When performing data analysis for these types of situations, the life-stress relationship model must take into account the cumulative effect of the applied stresses. Such a model is commonly referred to as a cumulative damage or "cumulative exposure" model. ReliaSofts ALTA PRO software supports the use of the cumulative damage model for data with time-varying stresses and with the recent release of Version 7, the software is now capable of analyzing data with multiple time-varying stresses. This article presents a summary of the four versions of the cumulative damage model available in ALTA 7 PRO, along with information about how these models may be applied.