| || Reliability and quality assurance experience in launcher hold and release system used in GSLV
Author : Singaravelu, J. ;Purushothaman, P. ;Thomas, Sojan ;Pillai, K.G.
Source : Defence Science Journal ; Vol:52(1) ; 2002 ; pp 21-25
Subject : 52 Space Research
Keywords : Launcher hiold systems ;System reliability ;GSLV;Quality assurance ;FMECA
Abstract : The launcher hold and release system (LHRS) was successfully used, for the first time, for GSLV-DI mission after thorough test and evaluation, in line with reliability and quality assurance (R&QA) requirements. Various R&QA techniques are applied to make LHRS failure-free. Failure mode effect and criticality analysis (FMECA) was used as a tool for identifying critical failure modes. Single-point failure modes (SPFMs) identified from FMECA are strengthened by design modifications and the same are verified by testing. Testing philosophy is tailored to have more number of tests at the system level. Capability demonstration tests and failure mode simulation tests were carried out during system qualification phase. Acceptance tests are done on the flight hardware at launch pad to demonstrate better confidence on the system. This paper illustrates how R&QA techniques complimented and added value at different stages in the development cycle of LHRS, by means of few case studies. Testing methodologies adopted and problems encountered during the development and qualification phases are described in brief. Various problems surfaced during preparation for flight are also discussed.
| || Quality management system : Some reflections
Author : Rao, Sudhakara K.
Source : Defence Science Journal ; Vol:56(1) ; 2006 ; pp 53-59
Subject : 629.7 Aeronautics;658 Management Sciences
Keywords : Quality management system;ISO 9000;Quality assurance;Reliability;Quality system;Fault tree analysis;FTA;QMS;Failure mode effects
Abstract : With the increasing demand for high quality products in every field, the demand for a good quality management system (QMS) in every organisation is increasing. This has since been well-appreciated by many organisations who have adopted QMS like ISO 9000, which has standardised the requirements for QMS. A well-organised QMS benefits the organisation in achieving its goals and sucess in its missions. In this paper, author's experiences in QMS and its implementation during his long tenure at ISRO, are briefly described. The author recalls a few incidents he faced during working on the projects of ISRO and DRDO, highlighting issues wrt quality and reliability, QMS, and ISO 9000 implementation. A few guidelines for effective QMS implementation are also suggested.
| || Evaluation of conducive environment for implementation of quality management system in an organisation
Author : Nayyar, V.K. ;Sekhar, K. ;Prasad, V.Anjaneya
Source : Defence Science Journal ; Vol:52(1) ; 2002 ; pp 47-57
Subject : 629.7 Aeronautics;629 Transport Vehicle Engineering
Keywords : Quality management ;Quality assurance ;QMS
Abstract : The ISO 9000 quality management system (QMS) is a philosophy. It is a consistent and logical approach, which if implemented and practiced in day-to-day activities, with total support from senior management, can lead to doing things right, first time-every time. Many organisations adopt ISO 9000 system as a milestone in their quest for quality management programme. Effectiveness of a system depends on the attitude of employees who are responsible for its implementation. Therefore, it is essential to know the prevailing environment in an organisation. To measure the attitude of employees, a survey through a wel1-designed questionnaire can be used as an effective tool. The items of questionnaire are framed on the basis of requirements of QMS. Attitude of employees is measured on a five-point scale, for each answer. Agreement or disagreement (positive or negative) directly measures the attitude of an employee on the said aspect Data analysis is carried out for establishing the validity of individual score to the total score of items across, using product moment correlation formula. Based on analysis of data, a comprehensive programme can be worked out for correcting the deficiencies observed through the attitude survey. This can also be used as a base for measuring the improvement of QMS in an organisation.
| || Quality Engineering in Aerospace Technologies : A Review
Author : Soni, J.S.;Narang, S.C.
Source : Defence Science Journal ; Vol:47(1) ; 1997 ; pp 5-18
Subject : 629.7 Aeronautics
Keywords : Total quality management ;Nondestructive testing;Metrology;Quality assurance
Abstract : "Quality assurance and reliability have assumed paramount importance in aerospace technologies due to stringent requirement of weight-to-strength considerations and the need for highly reliable systems. The techniques of inspection and testing have given way to the use of sophisticated reliability engineering, failure mode effects & criticality analysis, deign of experiments and total quality management concepts. The role of failure analysis to improve the quality on a continuous basis has been realised by all engaged in aerospace technologies. The number of simulation runs help to build up quality in design and development phase and obviate the need for extensive hardware testing. The techniques of metrology and nondestructive testing have been upgraded considerably during the last decade. Most of the manufacturing techniques, now being computer-aided, give consistent production and better quality. "
| || Ensuring software quality : Experiences of testing Tejas airdata software
Author : Rajalakshmi, Kavitha;Jeppu, Y. V.;Karunakar, K.
Source : Defence Science Journal ; Vol:56(1) ; 2006 ; pp 13-19
Subject : 629.7 Aeronautics;681.3 Computer Science
Keywords : Software quality;Software testing;Tejas;Light combat aircraft;Digital flight control computer software;Best practices;Software verification;Software validation;Safety critical code;Quality assurance;Airdata algorithm
Abstract : Two major safety-critical elements of the onboard software for the Tejas digital flight control computer software are the control laws and the airdata algorithm. The airdata algorithm computes essential parameters like static and dynamic pressures, altitude, speed, angle of attack, etc from the airdata sensor input. These parameters are used by the control laws to stabilise the aircraft and to provide the required uniform handling qualities over the complete flight envelope. The algorithm is provided by the Control Law Design Team and coded by the Software Design Group of Software House, ADA, Bangalore, in Ada language. The Independent Verification and Validation Group is responsible for ensuring that the software is bug-free and certifiable. A non-real time (NRT) test methodology has been developed in-house to stress test the onboard software. This paper gives an overview of the methodology used to carry out the NRT test of the airdata algorithm and some of the testing experiences.