Downtime has always affected the productive capability
of physical assets by reducing output, increasing operating
costs and interfering with customer service. By the 1960's
and 1970's, this was already a major concern in the mining,
manufacturing and transport sectors. In manufacturing, the
effects of downtime are being aggravated by the worldwide move towards just-in-time systems, where reduced
stocks of work-in-progress mean that quite small breakdowns are now much more likely to stop a whole plant. In
recent times, the growth of mechanisation and automation
means that reliability and availability have now also become
key issues in sectors as diverse as health care, data processing, telecommunications and building management.
The cost of maintenance has also been rising at a steady
pace over the past few decades, in absolute terms and as a
proportion of total expenditure. In some industries, it is
now the second highest or even the highest element of total
costs. So in only 40 years maintenance has moved from
nowhere to the top of the league as a cost control priority.
The importance of these two aspects of asset management means that many maintenance managers still tend to
view them as the only significant objectives of maintenance.
However, this is no longer the case, because the maintenance function now has a wide range of additional objectives. These are summarised in the following paragraphs.
Greater automation means that more and more failures
affect our ability to achieve and sustain satisfactory quality standards. This applies as much to standards of service