Domestic appliances are long-lived and relatively expensive products that c
ome under the new EC electrical waste recovery directive. In the UK, washin
g machines in particular tend to be unreliable; increasing the reuse of com
ponents could improve the economics of end-of-life operations. Trends in ap
pliance design are towards more sophisticated control and networking; this
makes adding functions to record data on the use of the machines feasible.
The data would also have value for life cycle environmental assessment.
This paper reports on the development of self-contained data acquisition un
its for washing machines based on a microcontroller and non-volatile memory
. The data has applications in design, marketing and servicing as well as e
nd-of-life. A batch of units have been manufactured and tested on limited f
ield trials in washing machines. Ten parameters are continuously monitored,
timed and/or recorded during appliance operation; error conditions are als
o logged for use during servicing. The data is then downloaded, either duri
ng servicing or at end-of-life; the dynamic data from use is combined with
static data from manufacture. The information system which links all partie
s interested in the data is the key aspect of life cycle data acquisition.
Two models are described which evaluate the economic benefits of adding suc
h functions to products: a steady-state model as used by previous authors w
ho were concerned with end-of-life product treatment and a more sophisticat
ed transient model that accurately reflects the limited life of designs. Re
sults show that in this case, more reusable components arise from servicing
rather than from end-of-life recovery of parts. The cost savings from incr
eased reuse are also estimated to be comparable to the additional cost of t
he system; greater savings could well arise from the use of the use data in
marketing. (C) 2001 Elsevier Science B.V. All rights reserved.