Subject: Techniques for Operational Efficiency

Chapter: 1 – Systematic Problem Solving and Quality Check Tools

Example of Problem in a companyIdeal Situation Real Situation

* Customers are satisfied * High-level of rejections and cancellations due to faulty products

* Workflow is free of bottlenecks * Over-use of raw material & scrap production due to faulty machinery* Resources are utilized for maximum

profits* Labor problems are minimized * Labor force is dissatisfied and over-

worked* Breakdown losses are reduced

Factors responsible for different problems:Factors Problems

Material & Equipment Over supply of raw materials and large inventory of sub-standard goods

Machine Frequent breakdown, repairing and high maintenance costsMethod Instructions for operating techniques missing, absence of

inspection during process, and use of wrong techniquesLabor Frequent strikes, careless attitude and over confidence

Types of problems:Types Examples of problems

Zero Problem As a floor manager in boiler area of a pesticide firm, you have to solve the problem of recurring accidents

Increase Problem The production of sports goods in your firm has been augmented by 55% in order to meet the demand created by National Athletic Field

Decrease Problem You have to solve the problem of high inventory so that you can minimize inventory costs incurred by your firm

Quality Check Tools 7 in number

1. Check-Sheets: Used to gather and interpret data in form of a list2. Graphs: Used to represent accurate status (Line / Bar / Pie)3. Histogram: Used to represent graphically the variations in a process (e.g.

time)4. Scatter diagrams: Used to represent correlation between two variables (e.g.

frequent accidents and tired workforce)5. Stratification: Used to group data to identify influencing factor (e.g.

stratification of absent labor in different groups like sick leave, dissatisfied worker, family issues, weather conditions, etc) <<<looks like an organization chart>>>

6. Ishikawa / Fishbone Diagram: Used to represent cause of a problem (root cause analysis). Also called cause-and-effect diagram

7. Pareto’s Analysis: Used to find most vital cause of a problem

Exercise 1.1: Which tool is used to resolve which problem?Problem Tool

The functioning of bottling equipment and canning equipment has to be monitored

Check-sheets

The most important cause of accidents in the factory has to be determined

Pareto’s Analysis

Data on the level of water table has to be depicted with respect to different factors

Stratification

The relationship between wages and productivity of labors in the factory has to be determined

Scatter Diagram

The variation in flavor of canned juices of different batches during the year has to be monitored

Histogram

Exercise 1.2: Possible causes of spoiled juices

To improve operational efficiency of a process / unit, the problem has to be found by defining gap between real situation and ideal situation.

Chapter: 2 – Managing Resources

Quality Circle (QC)Advantages of implementing QC

Enables staff to participate in key decisions (Staff feels empowered and the feeling of “us-versus-them” is removed effectively

Enables streamlining of processes by implementing the solutions proposed in Quality Circles

5-S technique for material / resource management: Seiri: Generates space, prevents unnecessary buying,

clarifies items in stock, reduces unnecessary maintenance of useless items and creates storage space

Seiton: Allows the materials to be retrieved easily, minimizes time taken to search and prevents unnecessary purchase

Seiso: Helps identify problem areas such as leaks and cracks, improves product quality, induces pride in employees and confidence in customers

Seiketsu: Minimizes errors, improves quality through zero defect, inculcates sense of pride among staff and ensures safe working conditions

Shitsuke: Sustenance of well-managed / well-organized work place, regular trainings to staff to maintain Standard Operating Procedures (SOP)

Advantages of 5-S technique for material / resource management: Focus on effective workplace management Standardized work procedures Simplification of work processes Reduction of clutter and non-essential Activities Improvement in Quality, Efficiency and safety

Exercise 2.1: Which 5-S technique is used by Pamela in which step?Problem Tool

Pamela sorted all her clothes and other items, discarded unnecessary items and returned the borrowed items

Seiri

Pamela Put the dirty clothes in laundry hamper. She then categorized toys and books and decided where to place them

Seiton

Pamela arranged all her clothes in proper order. The top drawer was reserved for school wear, middle one for home wear, and the next for socks and handkerchiefs

Seiso

Pamela is so excited by how her room looks that she now regularly cleans her room, puts dirty clothes in laundry and arranges books and toys

Seiketsu

Pamela’s mom is very pleased with the way Pamela keeps her room now. Although she doesn’t supervise Pamela’s daily cleaning, however, she often shows her how to organize items in a room

Shitsuke

Chapter: 3 – Statistical Process Control

Statistical Process Control (SPC) – The use of statistical analysis to improve quality by reducing unwanted variations in industrial and management processes and process capabilities.

Types of variations: Variations due to Random Cause – e.g., someone bumps your elbow when you

are singing Variations due to Assignable Cause – e.g., all documents in your computer are

changed into bar codes due to a virus attack

Random Cause Assignable CauseDifficult to identify Identified in operating conditions and can

be statistically controlledLarge in number Few in numberEconomically expensive to rectify since they need fundamental process changes

Economically inexpensive

Insignificant variation per cause, and is considered inherent part of process

Large amount of variation per cause

Examples: Poor lightening, bad workbench conditions, bad maintenance, poor machine conditions, fluctuations, etc.

Examples: faulty jigs and fixtures, poorly trained staff, defective raw material, etc

A process is capable (or under statistical control) when Assignable Causes have been identified and removed. SPC is used to:

Decide exactly how much variation is allowed in a process Ensuring defect-free manufacturing / processing by reducing variations Measure the consistency of processes Keep processes under control

Tools for SPC:Control Charts: Used to graphically represent quantitative measurements of a process and minimize variationsTwo types of control charts:

Control charts by variables Control charts by attributes

Interpreting Charts: Used to graphically control the variation in the processIn these charts there is a Center Line (CL) which represents the exact measurement of a variable required in a process. There are two more lines representing Upper Control Limit (UCL) and Lower control Limit (LCL). If a particular variation falls beyond

the area between UCL and LCL, it is considered a major variation. The control lines are set at a distance of three-sigma above (UCL) and three-sigma below (LCL) the center line.

Out-of-Control Processes:A continuous upward pattern indicates that the process is deteriorating with time. A common reason may be wear and tear of machines.

A cyclic trend (peaks and valleys) indicate that the process faced variations due to random causes such as worker fatigue, shift change, etc.

Peaks and valleys outside the control limits indicate the poorly trained workers, defective materials and frequent readjustments of the machines

Another graph which is an outcome of wrong samples being picked up rather than wrong processes followed. Apart from improper sampling, biased measurement may also cause such a type of graph

Exercise 3.1: What can be concluded from appearance of the graph?

This shows that the operators of the unit are not trained properly

Zone Tests:Zone tests are used to enhance the ability of the control charts to detect / study small shifts in the process. The dividing line of each zone is exactly one third the distance between center line and the UCL or LCL.

Nine points in Zone C or beyond: This pattern indicates that the process average has changed. It is a useful test to alert the quality control engineer to potential shifts in the process

Two out of three points in a row in Zone A or beyond: This pattern provides early warning of a process shift

[False-positive error rate = 2%]

Four out of five points in a row in Zone B or beyond: This is also an early warning indicator for a potential process shift

[False-positive error rate = 2%]

15 points in a row in Zone C: A small variability than is expected based on the Control Limit points in the graph

Eight points in a row in Zone A or B or beyond in either side of the centerline: This test indicates that different samples are affected by different factors, resulting in bimodal distribution of modes.

A process which is in statistical control need not necessarily produce product or services that meet the design specification of a product or service. To ensure that the process is meeting design specifications, we need to measure the process capability by calculating two indices of process capability – CP and CPKCP calculates the capability of a process by measuring overall process performance considering both positive and negative deviations.CP = (USL – LSL) / 6 sigmaTypical features of CP are:

These have no upper limits This doesn’t take into account any non-centering of a process Non-centering reduces margin of safety

CPK calculates the capability of a process by measuring clustering effect on the Upper and Lower specification limits.CPK = MIN [USL – x.bar / 3 sigma, (x.bar – LSL) / 3 sigma]

Exercise 3.2: Estimating Process Capability

Step 1: What is the CP of the machine?USL = 25 + 0.02 = 25.02LSL = 25 – 0.02 = 24.98Sigma = ?CP = (USL – LSL)/6 sigma = (25.02 – 24.98) / (6 * 0.01973) = 0.337

Step 2: What is the CPK of the machine?CPK = MIN [USL – x.bar / 3 sigma, (x.bar – LSL) / 3 sigma]

= MIN [(25.02 – 25.01) / (3 * 0.01973), (25.01 – 24.98) / (3 * 0.01973)]= MIN [0.1689, 0.5068]= 0.1689

Step 3: Is the process capable of meeting specifications? (Yes / No)No, because process variation exceeds specification limits when CP < 1

Step 4: Is the process correctly centered? (Yes / No)No, because CP < 1

Variations are not only unproductive but also expensive. For an operation to be a success it is very important to eliminate or at least minimize the variations

Chapter: 4 – Total Productive Maintenance

Total Productive Maintenance (TPM) is a continuous improvement strategy that involves an innovative approach to maintenance that improves and maximizes equipment effectiveness. Advantages of TPM:

TPM works with full support of management and cascades down to lowest level

TPM shows quick results but is not a quick one-time solution for all problems. TPM is proactive, as all employees are trained to anticipate problems that may

arise, instead of reporting only when there is a breakdown TPM works well in small group of employees and allows greater participation /

involvement, improved morale and development of those involved TPM increases equipment availability and quality and at the same time

decreases production costs and industrial accidents.

Pillars of Total Productive Maintenance:Jishu-Hozen: Begin by cleaning, inspecting, lubricating and performing corrective action on the machinery (daily chores) [Adv: System fell in place]Kobestu-Kaizen: Used to handle chronic problems, done by finding route cause of the problem, suggest and implement the most effective solution, test it and display the results. [Adv: Losses dealing with breakdown, speed, defects, setup, etc were removed]Planned Maintenance: Corrective, preventive and productive maintenance involved. Replacement of unsatisfactory equipments, improvements in design weaknesses were made to achieve zero defects and maximize MTBF (Meantime between failures)Quality Maintenance: Checklists were used to maintain quality and train workers on TPMInitial Equipment Control: Education & Training: Office TPM: TPM was used not just to maintain machines and upgrade skills of workers, but also for improving office administration. The TPM Standards for office include:

Uncluttered, paperless work desk Automated office space, where files are easily available Short and to the point meetings Optimum inventory available Minimal and non-repetitive manual work

Safety, Hygiene & Environmental Control: TPM Standards for zero accidents, zero diseases and zero pollution include:

Preparation of safety manual Audits on safety and hygienic conditions Safety work permit system and upgrading the pollution control system Safety award scheme Campaign on awareness of safety and environmental issues Regular monitoring of accidents Environmental review Eliminating spills and leakages Tree plantation

OPE = Overall Plant Efficiency (e.g., gone up by 1.5 times)OEE = Overall Equipment Effectiveness (e.g., gone up by 90%)

Exercise 4.1:

Steps for implementing TPM:1. Announcement by Upper Management about implementation of TPM in the

organization2. Initial Education and propaganda for TPM3. Setting up TPM Committees for TPM Pillars4. Establishing basic policy and target and master plan for TPM Implementation5. TPM kick-off events6. Implementing all TPM pillar activities7. Total application of TPM, monitoring implementation on continuous basis and

raising its level.

Exercise 4.2: