Editing Syntactic methods (section)

==Usage==

Syntactic methods are often used when [[formal methods]] are not an option, and are often a simpler and, more importantly, cheaper alternative. In non-[[mission-critical]] systems, [[formal methods]] may prove to be too expensive for the benefit they provide. The costs of modelling, personnel, execution and development may often outweigh the benefits gained by preventing possible failures. This approach revolves around the use of an ''abstract [[dependency graph]]'' which is created from the system in question. An abstract dependency graph is a [[directed graph]], a graph of [[vertex (graph theory)|vertices]] connected by one-way edges. Most often, the vertices and edges of the graph represent the inputs and outputs of functions in or components of the system. By inspecting the created abstract dependency graph, the developer can detect ''syntactic anomalies'' (or ''Preece anomalies'') in the system. While anomalies are not always defects, they often provide clues to finding defects in a system. Therefore, the anomalies in a system help point the developer in the right direction in finding defects.