Warranty period

Since these MPUs are used to control fuel-injection systems, it might be interesting to know the 24,000-km rehabiUty (the warranty period). Assuming an average speed of 80 km/h, 300 h of use are obtained. The rehabiUty would be estimated as... 

Durability. Grass-like surfaces intended for heavy-duty athletic use should have a service life of at least eight years, a common warranty period provided by suppHers. Lifetime is more or less proportional to the ultraviolet (uv) exposure (sunlight) and to the amount of face ribbon available for wear, but pile density and height also have an effect. Color is a factor generally uv absorption is highest with red fabrics and least with blue. In addition, different materials respond differendy to abrasive wear. These effects caimot be measured except in simulated field use and controlled laboratory experiments, which do not necessarily redect field conditions. 

A lot of modern equipment is almost maintenance-free but the user must be aware of what maintenance functions are required, whether these are within the scope of his own staff and where to get assistance. Where maintenance is contracted out, it is important that this should be carried out, at least for the warranty period, by the supplier. 

The design engineer would like to be able to predict the life of a component under given conditions on the basis of materials information or short-term tests. He can then choose his material such that the component will outlive its design life, its warranty period, or the lifetime expected by the market. Alternatively, he can set out a plan for maintenance or replacement. This book attempts to explain the methods currently used to make these predictions. 

PVC resists hydrolysis well but is naturally sensitive to light and UV. It must be protected by addition of anti-UV and other protective agents. In these cases, long warranty periods can be allowed, for example ten years and more. For a white, protected, rigid PVC, after natural weathering for 3 years in Michigan, the retention of impact strength is 68% and the yellowness index increases by 5. 

The extension of warranty periods is viable only if the performance and the durability of the product make it technically possible. 

CRC Press LLC warrants the physical disk(s) enclosed herein to be free of defects in materials and workmanship for a period of thirty days from the date of purchase. If within the warranty period CRC Press LLC receives written notification of defects in materials or workmanship, and such notification is determined by CRC Press LLC to be correct, CRC Press LLC will replace the defective disk(s). 

Be reasonable about agreeing to delivery dates suggested by the company. Otherwise, you may receive a system which is poorly made and the problems can linger through a finite warranty period and beyond. 

Knowing what software is used within a company is one thing. Knowing what the software license encompasses is a different story. It is not uncommon for an organisation who uses software to be unaware of issues such as the number of users allowed (named users or concurrent users), the license expiration date, product warranties, (period of) software support, consultancy (tariffs), delivery of upgrades (like Y2k-compliant versions) and so on. A contract management system should track the software (and likewise hardware) contracts. 

Spare parts (during warranty period, recommended spare parts list, spare parts supply after warranty period)... 

Maintenance. When the constmction phase ends and the owner takes over the project, the maintenance/ operation phase begins. The owner of the project usually takes over all responsibilities, but the contractor is usually bound by a warranty agreement. During the warranty period interaction between the owner and the contractor could be very frequent and intense. Beyond the warranty period, the physical structures require constant maintenance. A well-known example is the constant painting of the cables of the Golden Gate Bridge in San Francisco. 

ABSTRACT The field failure behaviour of components assembled in cars differs due to the specific load. Therefore, it is necessary to split complex systems into subsystems with similar failure behaviour. One example is the failure behaviour of electronic systems which mostly follows early failure behaviour. In contrast actors with mechanical components assembled in a car often show wear out failure behaviour. It is obvious that the different load of these components can cause serious problems predicting the joint failure behaviour. The reliabihty prognosis model presented in this article is based on warranty data. Thus the real failure behaviour of field usage can be described as accurate. By using several mathematical models the information of the warranty period can be used to predict rehability characteristics, such as the failure probability, even longer than the following warranty period (up to 10 years). 

The rehability prognosis model is based on warranty data which generally is recorded during the warranty period. Therefore iuformation about the manufacturing date, the registration date of the car, the time of failure and perhaps the incoming date is available. Additionally the mileage imtil the failure occurred is mostly available. To determine the specific load of a... 

As mentioned previously, the warranty providing was always accompanied by extra costs - warranty costs. These include costs related to settle aU valid claims during a warranty period, i.e. costs related to repair failures, which will occur during warranty period. These costs primarily include costs for work, costs for a new product, spare parts and used materials, costs related to transport claimed products, costs to compensate the customer (for example cost of providing a replacement during repair), administrative costs, etc. In general the warranty costs are influenced by the type and conditions o f warranty and product reliability. 

The amount of warranty costs depend on the quantity o f production covered by the warranty and the level of reliability of individual products. To be specific, the amount of warranty costs depends on the number of product failures covered by the warranty and costs related to settle individual claims during the warranty period. 

In the case of a one-dimensional non-renewing free-replacement warranty, on the premise that the perfect repair will be done, it is possible to predict the mean number of failures of one product during a warranty period using the renewal ftmction (Bhschke Murthy 1994, 1996, Rigdon Basu 2000) ... 

As an initial step it is necessary to predict the mean number of failures of all products sold in week s, which will occur in week w - [A ,s]. This value can be predicted using Equations (1), (2) or using other procedures. Equations (1) and (2) are vahd if the random variable (time elapsed fi om the product sale) has a continuous character. This fact is to be considered when predicting. The mean number of failures of all products sold in week s, which will occur in week w, is the difference between the predicted number of failures at the begirming and the end of week w. Given the warranty definition, the failures which will occur after the expiration of the warranty period ww are not taken into consideration, and for w-r > wiy theii[iV ,s] = 0. 

For the needs of time development analysis of the number of failures during the warranty period it is useful to divide the warranty period into individual periods that may be months, weeks or days. The choice of the period length depends on the specific situation. In this article the week was chosen. The variable w, which represents the time elapsed from the product sales launch, was established. The variable w takes values 1,2, etc. In the weekw = 1 the sales of the product was launched (the first product was sold). Also the variable a, which represents the age of the particular product (time elapsed from the product sale, counted in weeks), was established. The variable a takes values 0,1, etc. and for the week in which the particular product was sold the variable a = 0. Using the mentioned variables it is possible to determine the week in which the specific product was sold ... 

As the next step it is necessary to carry out a prediction of costs related to settling individual claims, i.e. costs related to repair individual failures during a warranty period. The mentioned costs can be divided into the following main components ... 

---