Statistical Process Control (SPC) Methods. Statistical process control (SPC) monitors specified quality characteristics of a product or service so as: To detect whether the process has changed in a way that will affect product quality and. To measure the current quality of products or services. Control is maintained through the use of control charts.
The underlying basis of criticism of GDP as a measure of welfare is the divergence between the critic's values and market values. The critics make an implicit assumption, or, quite possibly, a conscious presumption, that the former values are superior, if not far superior, to those of the latter.
Media caption The BBC's Declan Curry explains just what GDP stands for, and why we should care GDP, or Gross Domestic Product, is arguably the most important of all economic statistics as it attempts to capture the state of the economy in one number. Quite simply, if the GDP measure is up on the previous three months, the economy is growing. If it is negative it is contracting.