section_path: Methodology/Problem solving
section_name: Problem solving
paragraph_text: Problem solving
  
  Engineers use their knowledge of science, mathematics, logic, economics, and appropriate experience or tacit knowledge to find suitable solutions to a particular problem. Creating an appropriate mathematical model of a problem often allows them to analyze it (sometimes definitively), and to test potential solutions.
  
  More than one solution to a design problem usually exists so the different design choices have to be evaluated on their merits before the one judged most suitable is chosen. Genrich Altshuller, after gathering statistics on a large number of patents, suggested that compromises are at the heart of " low-level " engineering designs, while at a higher level the best design is one which eliminates the core contradiction causing the problem.
  
  Engineers typically attempt to predict how well their designs will perform to their specifications prior to full-scale production. They use, among other things: prototypes, scale models, simulations, destructive tests, nondestructive tests, and stress tests. Testing ensures that products will perform as expected but only in so far as the testing has been representative of use in service. For products, such as aircraft, that are used differently by different users failures and unexpected shortcomings (and necessary design changes) can be expected throughout the operational life of the product.
  
  Engineers take on the responsibility of producing designs that will perform as well as expected and, except those employed in specific areas of the arms industry, will not harm people. Engineers typically include a factor of safety in their designs to reduce the risk of unexpected failure.
  
  The study of failed products is known as forensic engineering. It attempts to identify the cause of failure to allow a redesign of the product and so prevent a re-occurrence. Careful analysis is needed to establish the cause of failure of a product. The consequences of a failure may vary in severity from the minor cost of a machine breakdown to large loss of life in the case of accidents involving aircraft and large stationary structures like buildings and dams.