Obsolescence Definition

Obsolescence isn’t an uncommon word – a Google search finds more than 5.7 million entries.  However, in the engineering design and product support context it has several different meanings.  First, the dictionary definition of obsolescence is the condition of no longer being used or useful. This definition is not inconsistent with the definitions that follow, but it is also not specific enough to provide much value in a product support context.

Planned Obsolescence – we hear this a lot.  Planned obsolescence refers to products (usually consumer products) that are designed to be rendered obsolete by the introduction of another product that has more functionality, higher performance, smaller size, and/or costs less.  Planned obsolescence is a strategy sometimes followed by companies that design and manufacture consumer electronics.  Planned obsolescence is often confused with “made-to-break” products [1].  Made-to-break products are products that are intentionally designed or manufactured to fail at some point in the future (nominally after the warranty has ended) forcing the customer to purchase a new product.

Sudden or Inventory Obsolescence - Sudden or inventory obsolescence occurs when the product design or system part specifications changes such that existing inventories of components (e.g., spare parts) are no longer required.  This type of obsolescence has been studied in the operations research literature.

  

DMSMS or Procurement Obsolescence – DMSMS (Diminishing Manufacturing Sources and Material Shortages) obsolescence is the loss or impending loss of original manufacturers of items or suppliers of items or raw materials [2].  This type of obsolescence is caused by the unavailability of technologies or parts that are needed to manufacture or sustain a product.  DMSMS means that due to the length of the system’s manufacturing and support life and possibly unforeseen life extensions to the support of the system, the necessary parts and other resources become unavailable (or at least unavailable from their original manufacturer) before the system’s demand for them is exhausted.  DMSMS obsolescence is the opposite of sudden or inventory obsolescence.

Planned obsolescence is a strategy followed by product manufacturers, DMSMS obsolescence is a situation forced upon system sustainers (these two types of obsolescence are not the same).  DMSMS obsolescence may be the result of the planned obsolescence of products that drive the market for specific types of parts, e.g., if your long field life system depends on the same parts that cell phones depend on, then planned obsolescence strategies for cell phones drive the DMSMS obsolescence of the parts you depend on.  The “poster child” for DMSMS type obsolescence is electronic parts.  For some electronic parts the planned obsolescence of particular products is the primary driver behind the part’s obsolescence, but the discontinuance of parts is also simply the result of falling demand that makes it more profitable to dedicate manufacturing resources to other products, or changes in ownership of product lines or companies.

All of the types of obsolescence defined above are relevant for real product and system segments.  While it is easiest to think of these as impacting hardware, obsolescence also has a significant impact on software [3], materials, and even the human workforce [4]. 

[1] Slade, G. (2006). Made to break: Technology and obsolescence in America, Harvard University Press.

[2] Sandborn, P. (2008). Trapped on technology's trailing edge, IEEE Spectrum, 45(1), pp. 42-45, April.

[3] Sandborn, P. (2007).  Software obsolescence - Complicating the part and technology obsolescence management problem, IEEE Transactions on Components and Packaging Technologies, 30(4), pp. 886-888, December.

[4] Sandborn, P. and Prabhakar, V.J. (2015).  Forecasting and impact of the loss of the critical skills necessary for supporting legacy systems, IEEE Transactions on Engineering Management, 62(3), pp. 361-371, August.