This chapter discusses the problems of different commercial programmes, and the underlying principles include the use of standard problems with a known solution, the use of basic engineering principles and the adoption of different programmes or even methods. The different types of subsurface information required for design include, but are not limited to, the following: Based on the site investigation results, the suitability of the proposed development can be assessed, and detailed analysis and design can be carried out subsequently. Actually, some engineers believe more in in-situ tests than laboratory tests, based on their engineering experience. Actually, some experienced engineers do not specify any laboratory tests in the investigation process, but rely totally on in-situ tests for some simple light structures. One interesting example is an engineering report submitted by an engineer for professional examination in Hong Kong. Part of the design involved a beam supported simply at two ends with several point loads and a distributed load.