ncp 27

NCP 27/ CBCM 7:CONSTRUCTION QUALITY MANAGEMENT: : 

NCP 27/ CBCM 7:CONSTRUCTION QUALITY MANAGEMENT: Prof. Sanjay Bhoyar Faculty, NICMAR,Pune

Quality: : 

Quality: The totality of features & characteristics of a product or service that bears on it the ability to satisfy a consumer’s need, at a reasonable cost. Quality is an indicator of fitness for use

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The duty of engineers & technical specialists is to prepare, revise & improve, systematically & methodically, the standards that will enable their companies to supply society with products/ structures as economically as possible

Major aspects of a construction project: : 

Major aspects of a construction project: Time Cost Quality Safety

Factors that adversely affect quality of construction: : 

Factors that adversely affect quality of construction: Designs that are difficult to build Poor quality labour Poor quality supervision Improper contract documentation Unrealistic constraints of time & cost Poor communication

Quality Management System (QMS): : 

Quality Management System (QMS): QMS refers to all plans, processes & activities Developed to achieve the intended degree of conformance in the design & execution of a project To achieve proper balance between quality attained vis-à-vis the desired quality

QMS development : 

QMS development Planning Design Procurement Construction Inspection Owner formulates,develops QAP Design consultant Suppliers develop their own QC methods and QA programme Contractor submits QA, QC Inspection and testing agencies

Importance of QMS in construction: : 

Importance of QMS in construction: Inadequate management of design: frequent changes in design,drawing and specifications Incorrect/Inadequate specifications at the tender stage Poor supervision: personnel deployed unaware of the quality parameters,documentation,supervision Lack of communication: between client-contractor,lack of formal communication system Delegation of authority and responsibility Lack of training in quality.

Elements of Quality: : 

Elements of Quality: Quality Characteristics: Quality of Design: Quality of Conformance: These elements together determine the quality of the final product

Priority of quality characteristics -(Quality weighting): : 

Priority of quality characteristics -(Quality weighting): Each characteristic is important But, each characteristic is not equally important 10-20%: major importance (A) 20-30%: minor importance (B) 60-70%: slight importance (C)

Types of quality standards/ levels: : 

Types of quality standards/ levels:

Economics of Quality of Conformance: : 

Economics of Quality of Conformance:

Aspects of quality: : 

Aspects of quality: Quality Engineering: Identifying quality characteristics, their requirements & the techniques/ methods to achieve them Quality Control: The operational techniques & activities used to ascertain that an established level of quality has been achieved & maintained. Quality Assurance: The planned & systematic actions necessary to provide adequate confidence that a product or service will satisfy the given requirements

Quality control (QC): : 

Quality control (QC): The operational techniques & activities used to ascertain that an established level of quality has been achieved & maintained. It is the phase in which the quality characteristics contemplated in the design phase are actually built into the product

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QC constitutes: Identification of the quality requirements of the product/ structure Setting up standards, procedures, documents etc Detecting deviations from the standards set earlier Provide feedback & appropriate corrective measures

5 ‘M’s of QC: : 

5 ‘M’s of QC:

QC process: : 

QC process: Study carefully all the documents related to the construction project Drawings Designs Specifications Contract documents Specifications & guidelines given by BIS or any other regulatory agency/ code Understand thoroughly the purpose of the project & the quality parameters envisaged in the design Any ambiguities, contradictions etc shall be clarified from concerned authorities

QC process… : 

QC process… Study the project organization & understand who is responsible for which particular aspect of quality Prepare checklist, related to quality requirement, for each item of construction Set up procedure for ensuring the quality in a proper sequence Evolve a system of documentation & reporting Obtain required approvals at appropriate stages from the competent authorities Initiate the corrective actions, if required, & obtain fresh approvals

Stages of QC: : 

Stages of QC: Issues of QC arises in all the functional areas of construction activities Design control Procurement control Process control Certification of work Non-compliance

Tools for QA/QC: : 

Tools for QA/QC: Method statements Checklists Inspection Testing Statistical QC Quality Audit

Construction method statement: : 

Construction method statement: Step-by-step procedures of execution of a particular construction work/ activity Includes Preparatory works Mixing of materials Erecting of temporary structures Positioning & operations of equipment Step-by-step execution Precautionary actions Finishing works Protection works

Importance of CMS: : 

Importance of CMS: Enables the construction team in execution of works Identification & allocation of resources Provides the basis for preparing checklists For construction team For inspection

Checklist: : 

Checklist: Ready-reference for execution & inspection Supports the systematic execution of works through CMS Objective assessment of the requirements for ensuring safe, hassle-free, & correct execution Includes the list of questions, to be answered objectively as yes/no/NA Questions are so framed, as to assess the capability of the process to produce the desired results

Types of checklists: : 

Types of checklists: Checklist for approval of source of materials Checklist for site activities civil works Mechanical & electrical works Checklist for plant/ machinery set up Checklist for lifting, movement & placement of different structural components Checklist for post construction activities

Inspection & Testing: : 

Inspection & Testing: Inspection: Qualitative assessment of the work (including quality characteristics) Observation Recording Verification Testing: Quantitative assessment of the quality characteristics Sampling Testing verification

Role of inspection in QC: : 

Role of inspection in QC: Inspection of materials Raw materials Inspection of temporary structures/ installations Inspection during work Process inspection In-process products/ structures Inspection of completed work Finished product/ structures Final inspection

Importance of inspection: : 

Importance of inspection: Inspection reveals quality of materials Defective materials Prevents defective materials going in process Inspection reveals improper implementation of procedures Defective workmanship Need for improvement Inspection provides appropriate information for QC & appropriate feedback for quality improvement What to control What to improve Inspection reveals the requirement/ need for testing

Testing: : 

Testing: Verification that determines the capability of an item to meet predetermined requirements by subjecting the item to a set of measurable operating conditions. Quantitative assessment of the quality characteristics

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Raw materials In-process materials Semi-finished structures/ structural components Finished structures

Types of tests: : 

Types of tests: Field tests Laboratory tests Destructive tests Non-destructive testing

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Statistical Quality Control

Statistical concepts: : 

Statistical concepts: Population: A set of all items Sample: A subset of population A representative of population Parameter: Characteristic of population under study Statistics: Deals with the collection, classification, analysis & making inference from data or information Data collection: Direct observations Indirect observations

Relation between Data, Sample, & Population: : 

Relation between Data, Sample, & Population: Take action with regard to population. Infinite population Finite population Action Action

Two types of Cause of Dispersion: : 

Two types of Cause of Dispersion: Common/ Random/ Chance causes: Variation in results even when everyone is operating according to standards (i.e. process is under control) Cannot be identified Unavoidable causes Assignable causes: Abnormality when work standards are disobeyed or something outside the standards happens (i.e. process is not under control) Can be precisely identified Avoidable causes Uncontrolled variability

Categories of SQC: : 

Categories of SQC: Descriptive statistics Describe quality characteristics & relationships Statistical process control (SPC) Inspecting a random sample of the output from a process to judge whether the process is functioning properly or not Acceptance sampling Randomly inspecting a sample to decide the acceptance/ rejection of the entire lot

Descriptive statistics: : 

Descriptive statistics: Describes quality characteristics of a product or a process Measures of central tendency Mean Measures of variability Range Standard deviation Small SD/ Range – observations are closely clustered around the mean Large SD/ Range – observations are spread out Distribution of data Symmetric: Normal distribution Skewed: Beta distribution

Statistical Process Control (SPC): : 

Statistical Process Control (SPC): Use of descriptive statistics to monitor the quality of the product & process Determining the common/ random variation To ensure that the process is under control/ in a state of control Control charts

Control charts: : 

Control charts: A graph showing whether a sample of data falls within the common/ normal range of variation Data is assumed to exhibit a normal distribution Upper control limit (UCL) Lower control limit (LCL) Process is under control when all the data points are within control limits

Quality Control Chart: : 

Quality Control Chart:

Some rules for identifying an Out-of-Control Process: : 

Some rules for identifying an Out-of-Control Process: If a single point plots outside the control limits If 2 out of 3 consecutive points fall outside the 2-sigma warning limits on the same side of the center line If 4 out of 5 consecutive points fall beyond the 1-sigma limit on the same side of the center line If nine or more consecutive points fall to one side of the center line If there is a run of six or more consecutive points steadily increasing or decreasing

Types of Control Charts: : 

Types of Control Charts: Control charts for variables: To monitor characteristics that can be measured, & Have a continuum of values Control charts for attributes: To monitor characteristics that have discrete values, & Attributes require only a single decision Good or bad Acceptable or unacceptable Counting the number of defects

Acceptance Sampling: : 

Acceptance Sampling: Randomly selecting certain number of items from a lot/ batch To decide whether to accept or reject the lot/ batch Sampling plan: Lot size (N) Sample size (n) Acceptable quality level (AQL) Single sampling Double sampling

Acceptance Sampling by Variables: : 

Acceptance Sampling by Variables: Quality characteristics defined by continuously measurable quantities Strength, density, length, thickness, degree of compaction, temperature, etc More efficient than sampling by attributes Fewer samples are required to obtain a desired level of quality control

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Acceptance lot quality can be defined by an upper limit (U), or a lower limit (L), or both Normal distribution is used to determine the probability of acceptance

Acceptance Sampling by Attributes: : 

Acceptance Sampling by Attributes: The acceptance or rejection is based on the number of defective or non-defective items in the sample Testing a pre-defined number of sample items from a lot Each lot is tested to determine if it satisfies a minimum acceptable quality level (AQL)

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If, N= lot size n= sample size x= number of defective items in the sample If, p= the actual fraction of defectives in the lot Then, q = 1-p If , r = acceptable no. of defectives Then, The probability of accepting the lot is given by: Pa =

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Producer’s risk: Probability that acceptable lots might be incorrectly rejected Consumer’s risk: Probability that deficient lots might be incorrectly accepted

Operating characteristic (OC) curve: : 

Operating characteristic (OC) curve: Pa =

Designing a sampling plan: : 

Designing a sampling plan: Large sample sizes are required to ensure large probabilities of zero defective items Devising an acceptable sampling plan requires a trade-off between The objectives of risk minimization, & The cost of testing

Total Quality Control: : 

Total Quality Control: In traditional approach Acceptable Quality level Allowable fraction of defective items In TQC No defective items are allowed anywhere in the construction process Commitment to quality in all parts of an organization TQM

Economic benefits of TQC: : 

Economic benefits of TQC: Reduction in Inventory expenses Rework cost Scrap expenses warranties Improvement in worker commitment & enthusiasm Customers’ appreciation & willingness to pay premium

Difficulties in application to Construction: : 

Difficulties in application to Construction: Endorsing the goal of zero defect is difficult, Unique nature of each project Variability in the workforce Multitude of subcontractors Investment in training & education Nevertheless, commitment to improved quality can pay rich dividends

QC Cycle: PDCA : 

QC Cycle: PDCA

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PDCA cycle ISO 9000 PLAN DO ACT CHECK Continuous Improvement Continuous improvement ?

From QC to TQM: : 

From QC to TQM: A gradual shift over a period of time Quality is everybody’s job Customer is king

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Quality Control Quality Management Past Future Detect faults Prevent errors Look for guilty persons Look for defaults in the processes Accuse Help, Moderate, Facilitate Punish Motivate Micro-management Systematic management Transition towards TQM

Principles of TQM: : 

Principles of TQM: 1] ‘Customer Focused Approach’ Towards all activities and processes in an organization,ensuring that all are concerned with the customers needs 2] Strategic Planning and leadership For achieving customer focused quality targets in all activities and processes. L’ship should be able to make long term commitments to customers, employees, vendors, etc.

Cont… : 

Cont… 3] Cross Functional horizontal processes Restructuring of vertical process to cross functional horizontal process where in the clear view of customers can be established throughout the hrchy. A shift from individual to team-work 4] Internal customer system Creating a culture of working through ICS where each stage in process, and each person in the process can be linked as customers to each other in the chain of activities for production and delivery of goods & services. This helps understand the customers more deeply

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5] Continuous Improvement Concerned to all the processes and activities-leading to total customer satisfaction & a competitive edge. It is based on the fact that there is no end to improvement and should be continuously perused for performance excellence Think ‘OUTSIDE THE BOX’ 6] Training and development People are at the core of every process and activities of the organization It is the people who drive the TQM T & D on these grounds are mandatory

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7] Empowerment and teamwork of people To provide people with opportunity to learn,apply and practice their skills,creativity and knowledge Team approach towards work & cross-functional process management are vital Objective – To eliminate bureaucracy and delay in decision making as it adversely effects customer services.

Benefits of TQM : 

Benefits of TQM First & foremost benefit – Customer satisfaction Reduced cost of construction – overshadowed the myth Increases employee productivity and equipment productivity as well – increases efficiency of operation. Reduces mistakes and increases monetary savings through more efficient use of scarce resources

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Increase pride of workmanship amongst individual workers Better justification for budgets due to more efficient operations Increased readiness of the whole organization Streamlined maintenance and production process Better profitability

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ISO 9000:2000 63 ISO 9001:2000

New definition of quality: : 

New definition of quality: “Degree to which a set of inherent characteristics fulfils requirements” ISO 9000:2000, Quality management systems – fundamentals and vocabulary.

WHAT IS ISO : 

WHAT IS ISO It is a set of international standards prepared by the International Organisation for Standardization, a voluntary body that has representation from more than 100 countries and is headquartered in Geneva

Purpose of ISO : 

Purpose of ISO Harmonise standards at international level. Ensure consistency of output Make organisations more competitive by reducing wastage at various places in the company

ISO – 9000:2000 Family : 

ISO – 9000:2000 Family The previous 20 standards are now replaced by four: ISO 9000: Quality Management Systems – Fundamental & Vocabulary ISO 9001: Quality Management System – Requirements

ISO – 9000:2000 Family… : 

ISO – 9000:2000 Family… ISO 9004: Quality Management System – Guidance for performance improvement ISO 9011: Guidelines for auditing quality & environmental management systems.

ISO-9001:2000 : 

ISO-9001:2000 Major Clauses in new ISO 9001:2000 Quality Management Systems Management Responsibility Resource Management Product Realization Measurement, Analysis & Improvement

Quality Management Principles : 

Quality Management Principles Customer Focus Leadership Involvement of People Process Approach System Approach Continual Improvement Factual Approach to Decision Making Mutually Beneficial Supplier Relationship

Types of documents for effective implementation: : 

Types of documents for effective implementation: Quality manual Procedures Work instructions, & Forms & Records

Benefits of ISO Standards : 

Benefits of ISO Standards Customers Company Employees

Customers : 

Customers Quality Service Increased Confidence in Service Less number of non-compliance's. Improved Supply/Consistent Quality Helps in Planning Activity Competitive Pricing/Lead Time Reduction

Company : 

Company Reduced Number of defects Increased Customer Satisfaction Consistency in Output Assured Customer/Market Share Reduction in costs due to reduction of defects Involvement of Personnel and consequent Higher Productivity

Employees : 

Employees Defined Directions Improved Performance Better and improved relation. Increases Motivation Job Satisfaction Involvement Pride of working in an ISO 9000 company.

Quality circles: : 

Quality circles: A group of 5-15 workers who meet on a frequent basis Focus on solving productivity, quality, safety, & other work-related problems A circle leader acts as liason between the workers & the management

Principles of Quality Circles: : 

Principles of Quality Circles: Volunteering Regularity Four- dimensional process Problem identification Problem selection Problem analysis Problem solution Self improvement

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Synergy Sincerity of purpose By management, as well as workers General application Simplicity Social responsibility

Structure of Quality Circles: : 

Structure of Quality Circles: Steering committee Senior management personnel Facilitator Senior officer of the department May cover 3-4 circles Circle leader Co-ordinating agency Central information point for quality circle activities of the entire organization

Quality costs: : 

Quality costs: Prevention costs Incurred in planning, implementation & maintaining a quality system Appraisal costs Associated with measuring & evaluating materials, components, products/ structures Testing & inspection Internal failure costs Costs of non-conforming materials, components, products, before transferring to customer Scrap, rework, downgrading costs External failure costs Costs of non-conforming components/ products, after transferring to customer Due to customer complaint Investigation, adjustment, repair, replacement Warranty charges, litigation

Quality audit: : 

Quality audit: To judge the effectiveness of quality management programs To verify compliance & suggesting improvement

Purposes of auditing: : 

Purposes of auditing: Suitability quality audit In-depth evaluation of the quality program against a reference standard Conformity quality audit Thorough evaluation of the operations & activities within the quality system To evaluate the degree to which they conform to the defined quality policies & procedures

Types of quality audits: : 

Types of quality audits: System audit Extensive audit Process audit Auditing one or more processes Product audit Final product/ structure Internal audit External audit Third party audit

Juran's Ten Steps To Quality Improvement: : 

Juran's Ten Steps To Quality Improvement: Build awareness of the need and opportunity for improvement. Set goals for improvement. Organize to reach the goals (establish a quality council, identify problems, select projects, appoint teams and designate facilitators). Provide training. Carry out projects to solve problems. Report progress. Give recognition. Communicate results. Keep score. Maintain momentum by making annual improvement part of the regular systems and processes of the company.

6 ‘C’s of Quality Control: : 

6 ‘C’s of Quality Control: Comprehension Commitment Competence Communication Correction Continuance

Deming's 14 points: : 

Deming's 14 points: Create constancy of purpose for improvement of product and service. Adopt the new philosophy. Cease dependence on inspection to achieve quality. End the practice of awarding business on the basis of price tag alone. Instead, minimize total cost by working with a single supplier. Improve constantly and forever every process for planning, production, and service. Institute training on the job. Adopt and institute leadership. Drive out fear.

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Break down the barriers between staff areas. Eliminate slogans, exhortations, and targets for the workforce. Eliminate numerical quotas for the workforce and numerical goals for management. Remove barriers that rob people of pride and workmanship. Eliminate the annual rating or merit system. Initiate a vigorous program of education and self-improvement for everyone. Put everybody in the company to work to accomplish the transformation.

Light- weight concrete: : 

Light- weight concrete: Low density 3 – 20 kN/M³ Advantages: Reduction of dead load Faster construction Reduction in haulage & handling costs Low thermal conductivity Use of industrial waste Inclusion of air in concrete

Methods: : 

Methods: Light weight aggregate concrete By replacing usual mineral aggregates by cellular porous or light wt aggr Natural light wt aggr Pumice Organic aggr, saw dust Artificial light wt aggr Cinders, clinkers Sintered fly ash Foamed slag Brickbats Bloated clay (glass & shale are heated to point of fusion)

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Aerated concrete Gas concrete/ foam concrete/ cellular concrete By introducing gas or air bubbles By gas formation by chemical reaction during plastic state By mixing preformed stable foam with the slury By using finely powdered metal, like aluminium Siporex

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No-fines concrete By omitting sand Only single sized CA (10-20 mm) Aggr: cement ratio 6:1 to 10:1

Relation between strength & density: : 

Relation between strength & density: Factors governing density: Composition of materials Quality of ingradients Aggr: cement ratio Fine to CA ratio Size & Composition of CA Degree of compaction Method of compaction

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Factors governing strength: Density W/C ratio Aggr: cement ratio Composition of CA Workability Degree & method of compaction curing

IS:456 : 

IS:456 Section 2: Materials, Workmanship, Inspection & Testing Cement Admixtures Aggregates Water Reinforcement Workability Durability requirements Design mix

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Batching Mixing Formwork Reinforcement placing Strength of concrete Frequency of sampling Test results Acceptance criteria Inspection & testing of structures

Summary: : 

Summary: For quality work, Ensure proper work culture & ethics Integrity Everyone to concentrate on doing job better & better every single day Work ceaselessly towards the quality objectives Follow an organizational approach Continual improvement

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Thank You

Contact NICMAR: : 

Contact NICMAR: www.nicmar.ac.in 022-27291342 Prof. Sanjay Bhoyar sanbhoyar@nicmar.ac.in 9545440255