Tangential Service

Sometimes a service can be provided as a cheap or unimportant side-effect of something else.

I was struck by this thought when I saw a news story indicating shortages of Molybdenum-99, a radioactive isotope used for medical scans. There are five nuclear reactors in the UK that normally produce this isotope as a by-product, but two of the five are currently down for scheduled maintenance and a third has encountered an unexpected problem. [Isotope problem may delay scans, BBC News, 5 Sept 2008] Nuclear medicine is dependent on rare isotopes produced in nuclear reactors; however, the nuclear reactors' primary purpose is the generation of electricity and not the supply of radioactive materials to hospitals.

Here's another example. Sally is planning to drive her daughter to a swimming gala, so she offers to drive her daughter's school friend as well. In the morning of the gala, Sally's daughter has a fever and cannot swim. It is now too late for the friend's parents to make alternative arrangements. Is Sally morally obliged to stand by her promise to take her daughter's friend, although she would prefer to stay at home with her sick daughter?

Here are the common factors in these examples

• A is providing a service to B
• This service is not (and never will be) the primary mission or purpose of A.
  
• B is dependent on this service
  
• Under normal circumstances, the cost to A of providing the service is negligible.
  
• If A's circumstances change, it may become inconvenient, expensive or impossible for A to provide the service to B.

I'm going to call services that fit this pattern tangential services, and I think there are important considerations for both providers and consumers.

• A may be unwilling to invest any resources in monitoring or improving the service. B might be willing to contribute some resources to improving the service (especially improving its reliability), but this may be difficult to manage.
• B needs to monitor the service, but may not have access to information that would provide advance warning of service problems (because this is private to A).
  
• Service level agreements may be weakly specified or completely absent. A may have no formal obligations to B.
  
• Under normal circumstances, everyone is happy. There may be a sudden jump from happy (mutally convenient, value-adding) to unhappy (inconvenient to A and/or B, unexpected cost).

There is of course nothing wrong with providing or consuming tangential services. For the provider, it may be a bit of extra revenue or an opportunity to provide some social value. For the consumer, it may represent a significant cost-saving, or provide access to something that might otherwise have been impossible. However, it is important to understand the implications of a service's being tangential, and to think through questions of service levels, liabilities and contingency plans.