Computer-aided maintenance (not to be confused with CAM which usually stands for Computer Aided Manufacturing) refers to systems that utilize software to organize planning, scheduling and support of maintenance and repair. A common application of such systems is the maintenance of computers, either hardware or software, themselves. It can also apply to the maintenance of other complex systems that require periodic maintenance, such as reminding operators that preventive maintenance is due or even predicting when such maintenance should be performed based on recorded past experience.

Computer aided configuration

The first computer-aided maintenance software came from DEC

Digital Equipment Corporation

Digital Equipment Corporation was a major American company in the computer industry and a leading vendor of computer systems, software and peripherals from the 1960s to the 1990s...

 in the 1980s to configure VAX

VAX

VAX was an instruction set architecture developed by Digital Equipment Corporation in the mid-1970s. A 32-bit complex instruction set computer ISA, it was designed to extend or replace DEC's various Programmed Data Processor ISAs...

 computers. The software was built using the techniques of artificial intelligence

Artificial intelligence

Artificial intelligence is the intelligence of machines and the branch of computer science that aims to create it. AI textbooks define the field as "the study and design of intelligent agents" where an intelligent agent is a system that perceives its environment and takes actions that maximize its...

 expert system

Expert system

In artificial intelligence, an expert system is a computer system that emulates the decision-making ability of a human expert. Expert systems are designed to solve complex problems by reasoning about knowledge, like an expert, and not by following the procedure of a developer as is the case in...

s, because the problem of configuring a VAX required expert knowledge. During the research, the software was called R1 and was renamed XCON

Xcon

The R1 program was a production-rule-based system written in OPS5 by John P. McDermott of CMU in 1978 to assist in the ordering of DEC's VAX computer systems by automatically selecting the computer system components based on the customer's requirements...

when placed in service. Fundamentally, XCON was a rule-based configuration database

Database

A database is an organized collection of data for one or more purposes, usually in digital form. The data are typically organized to model relevant aspects of reality , in a way that supports processes requiring this information...

written as an expert system using forward chaining

Forward chaining

Forward chaining is one of the two main methods of reasoning when using inference rules and can be described logically as repeated application of modus ponens. Forward chaining is a popular implementation strategy for expert systems, business and production rule systems...

 rules. As one of the first expert systems to be pressed into commercial service it created high expectations, which did not materialize, as DEC lost commercial pre-eminence.

Help Desk software

Help desk

Help desk

A help desk is an information and assistance resource that troubleshoots problems with computers or similar products. Corporations often provide help desk support to their customers via a toll-free number, website and e-mail. There are also in-house help desks geared toward providing the same kind...

s frequently use help desk software that captures symptom

Symptom

A symptom is a departure from normal function or feeling which is noticed by a patient, indicating the presence of disease or abnormality...

s of a bug and relates them to fixes, in a fix database. One of the problems with this approach is that the understanding of the problem is embodied in a non-human way, so that solutions are not unified.

Strategies for finding fixes

1. The bubble-up strategy simply records pairs of symptoms and fixes. The most frequent set of pairs is then presented as a tentative solution, which is then attempted. If the fix works, that fact is further recorded, along with the configuration of the presenting system, into a solutions database.
2. Oddly enough, shutting down and booting
   Booting
   In computing, booting is a process that begins when a user turns on a computer system and prepares the computer to perform its normal operations. On modern computers, this typically involves loading and starting an operating system. The boot sequence is the initial set of operations that the...
   
    up again manages to 'fix,' or at least 'mask,' a bug in many computer-based systems; thus reboot is the remedy for distressingly many symptoms in a 'fix database.' The reason a reboot often works is that it causes the RAM
   Ram
   -Animals:*Ram, an uncastrated male sheep*Ram cichlid, a species of freshwater fish endemic to Colombia and Venezuela-Military:*Battering ram*Ramming, a military tactic in which one vehicle runs into another...
   
   to be flushed. However, typically the same set of actions are likely to create the same result demonstrating a need to refine the "startup" applications (which launch into memory) or install the latest fix/patch of the offending application.
3. Currently, most expertise in finding fixes lies in human domain experts, who simply sit at a replica of the computer-based system, and who then 'talk through' the problem with the client to duplicate the problem, and then relate the fix.