QUALITY

It is the application of six sigma principles in maintenance. Six sigma is a maintenance process

that focuses on reducing the variation in business production processes. By reducing variation,

a business can achieve tighter control over its operational systems, increasing their cost

effectiveness and encouraging productivity breakthrough.

Six sigma is a term created at Motorola to describe the goal and process used to achieve

breakthrough levels of quality improvement. Sigma is the Greek symbol used by statisticians to

refer to the six standard deviations. The term six sigma refers to a measure of process variation

(six standard deviations) that translates into an error or defect rate of 3.4 parts per million. To

achieve quality performance of six sigma level, special sets of quality improvement methodologies

and statistical tools developed. These improvement methods and statistical tools are taught to a

small group of workmen known as six sigma champions who are assigned full-time responsibility

to define, measure, analyze, improve and control process quality. They also facilitate the

improvement process by removing the organizational roadblocks encountered. Six sigma

methodologies improve any existing business process by constantly reviewing and re-tuning the

process. To achieve this, six sigma uses a methodology known as DMAIC (Define opportunities,

Measure performance, Analyse opportunity, Improve performance, Control performance). This

six sigma process is also called DMAIC process.

Six sigma relies heavily on statistical techniques to reduce failures and it incorporates the

basic principles and techniques used in Business, Statistics, and Engineering. Six sigma methodologies

can also be used to create a brand new business process from ground up using design for six

sigma principles.

SIX SIGMA MAINTENANCE PROCESS

The steps of six sigma maintenance are same as DMAIC process. To apply six sigma in

maintenance, the work groups that have a good understanding of preventive maintenance techniques

in addition to a strong leadership commitment. Six sigma helps in two principal inputs to the

maintenance cost equation: Reduce or eliminate the need to do maintenance (reliability of equipment),

and improve the effectiveness of the resources needed to accomplish maintenance. Following are

the steps involved in six sigma maintenance process.

Define

This step involves determining benchmarks, determining availability and reliability requirements,

getting customer commitments and mapping the flow process.

Measure

This step involves development of failure measurement techniques and tools, data collection

process, compilation and display of data.

Analysis

This step involves checking and verifying the data and drawing conclusions from data. It also

involves determining improvement opportunities, finding root causes and map causes.

Improve

This step involves creating model equipment and maintenance process, total maintenance

plan and schedule and implementing those plans and sc

Feedback control system

Project management.

Following are some computer based maintenance systems which can be implemented:

Job card system: It is essential to prepare a job card for each component to record the

maintenance work carried out or the work to be done. Job card shows the plant code, equipment

code, the job code, the nature of the jobs, the start time and finishing time of the card, man-hour

spent and etc. The use of computers facilitates the issue of job cards, recording of job history

and control of manpower.

Spare part life monitoring system: Under this system, information about a spare part

such as its description, anticipated life and date of its installation in equipment is recorded. As

and when a particular sparepart is replaced during breakdown failures or scheduled maintenance,

the updating of this information is done in their respective files stored in the computer. This helps

to prepare the following reports:

Spares repeatability in various machines indicating the performance of such spare parts.

Comparisons of the actual life with the estimated life of the spare parts.

Spare parts tracking system: In most of the cases maximum time is consumed in

procurement of spare parts. The total time required to rectify the breakdown is summation of

the time to identify the cause of the failure, time to determine the requirements of spare parts,

time to procure spare parts and the time to rectify the failure. In a computerised system, the

spare part tracking system is beneficial in getting required material at the earliest. A spare part

file is created that contains the information about the material code, spare part identification

number, the assembly or sub-assembly number and the place where the spare part is used.

This helps in knowing the current position about a particular spare part and facilitates timely

requirement for future demands.

SEITON—Organise

The concept here is that “Each items has a place, and only one place”. The items should

be placed back after usage at the same place. To identify items easily, name plates and coloured

tags has to be used. Vertical racks can be used for this purpose, and heavy items occupy the

bottom position in the racks.

SEISO—Shine the Workplace

This involves cleaning the work place free of burrs, grease, oil, waste, scrap etc. No loosely

hanging wires or oil leakage from machines.

SEIKETSU—Standardization

Employees has to discuss together and decide on standards for keeping the work place/

machines/pathways neat and clean. This standards are implemented for whole organization and

are tested/inspected randomly.

SHITSUKE—Self-discipline

Considering 5S as a way of life and bring about self-discipline among the employees of the

organization. This includes wearing badges, following work procedures, punctuality, dedication to

the organization etc.

PILLAR 2—JISHU HOZEN (AUTONOMOUS MAINTENANCE)

This pillar is geared towards developing operators to be able to take care of small maintenanc