An Efficient Failure-Based Maintenance Decision Support System for Smalland Medium Industries - Efficient Decision Support Systems: Practice and Challenges from Current to Future - page 202

ii. When the next maintenance is due for every machine;
iii. Which contractor should be called to perform the maintenance work;
iv. Estimates of man-hours required;
v. Description of the tasks involved and how much time is required;
vi. Lists of all required replacement parts and their locations;
vii. Forecast on the spare parts, tools and their costs;
viii. Re-order level of the machine parts and other accessories; and
ix. An estimate of the maintenance priorities and their impact.
The most prominent objective of the various techniques in maintenance DSS is to supply
vital data and evidence, to derive better strategies to minimize machine downtime and
maintenance cost. DMG is one of the famous techniques in DSS as suggested as follows.
5. Decision-making grid
The maintenance Decision-Making Grid (DMG), introduced by Labib (1998) acts as a map
where the performances of the worst machines are placed based on multiple criterions, i.e.
frequency of failures and downtime. The results provide guidelines for the action, which
will lead to the movement of machines towards an improvement of the maintenance
strategies with respect to multiple criterions. Labib (2004) defined the main input from the
failures for DMG analysis as follows:
i. The response time;
ii. The diagnostic time;
iii. The repair time; and
iv. Frequency of failures.
Based on the input, machines are mapped into a two-dimensional matrix and appropriate
maintenance strategies will then be implemented, such as total productive maintenance,
reliability-centred maintenance, design-out maintenance, condition-based maintenance,
fixed-time maintenance, etc.
There are many researchers who have studied the DMG and apply it in the equipment
management area. Among those, there are three selected reviews that are worth discussing
under this sub-section. In the first Labib (1998a) has introduced the DMG model to help
maintenance management identify breakdown maintenance strategies. In short DMG is a
control chart in two dimensional matrix forms. The columns of the matrix show the three
criterions of the downtime, whilst the rows of the matrix show another three criterions of
the frequency of the failures. The model consists of these three steps:
i. Criteria analysis;
ii. Decision mapping and
iii. Decision support.
Here, a better maintenance model for quality management can be formed by handling both
the rows and columns of the matrix respectively. The matrix offers an opportunity to decide
what maintenance strategies are needed for decision-making such as to practice Operate to
Failure (OTF), Fixed Time Maintenance (FTM), Service Level Upgrade (SLU), Condition-
based Maintenance (CBM), Designed-out Maintenance (DOM), Total Productive
Maintenance (TPM) and Reliability-centered Maintenance (RCM).
The second important review was undertaken by Fernandez et al. (2003), in which
implementation of DMG in CMMS was discussed in detail. They extended the theory of the
maintenance maturity grid and implemented it into a disk brake pad manufacturing