Chapter 14. The Effects of Fluctuations, Variability, and Uncertainty on the System


Uncertainty related to faults and disruptions is referred to as fluctuations. This word serves as a general term for all of the seemingly unexpected situations—problems, malfunctions, interruptions, and disturbances.

Sources of Fluctuations

Fluctuations can be classified by their source:

Demand fluctuations

  • Variability in demand

  • Seasonality

  • Technological changes and changes in preferences

For example, fluctuations in the development department of a high‐tech company might involve:

  • Technological uncertainty (knowledge gap)

  • Changes in customers' requirements

  • Unavailability of critical purchased items

  • Delays of subcontractors

  • Uncertainty of market demand

Evolution of Fluctuations in a Process

Consider the planning of a new line of services, products, or development as depicted in Figure 14-1 . Every task that enters the system (a patient receiving treatment, a request to develop a smart piece of software, or assembly in production) ...

Get Focused Operations Management now with the O’Reilly learning platform.

O’Reilly members experience live online training, plus books, videos, and digital content from nearly 200 publishers.