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 | A unified method of inspection and quality control
Author : Iyer, P.V.Krishna ;Bhattacharyya, M.N.
Source : Defence Science Journal ; Vol:8(1) ; 1958 ; pp 5-20
Subject : 519.2 Statistics
Keywords : Quality control
Abstract : It has been shown earlier that the mean and range charts used for S.Q.C. can be replaced by a single chart showing the largest and smallest values of samples taken from the machine at regular intervals. This chart designated as L-S chart has been found to be economical and efficient in many respects. The present paper shows that by modifying the sampling procedure, the S.Q.C. chart, besides providing information on the machine setting, tool wearing etc. for controlling the quality of the products collected during sampling intervals and thus enables us to dispense with 100 percent stage inspection which is in practice in the ordnance factories. The modification consists in taking one or two jobs from the machine at regular intervals and another four jobs at random from the products manufactured during every interval. The samples so selected are plotted on a chart against the specification limits. The collections during the different intervals will be accepted if all the four jobs are within the specification limits; otherwise screening will be done. Condition of the machine is judged mainly from the jobs taken from it. The experimental investigations conducted at Gun and Shell Factory, Cossipore show that this procedure works as effectively as the L-S chart and cent per cent inspection. |
| | Quality management system implementation at KELTEC : A case study
Author : Aniyan , S.
Source : Defence Science Journal ; Vol:52(4) ; 2002 ; pp 393-402
Subject : 629.7 Aeronautics
Keywords : Quality management system ;KELTEC ;Total quality management ;ISO 9000 certification ;ISO 9000 quality system ;Quality control
Abstract : The scenario of quality is expanding exponentially. In the present-day world, quality is now in the driver's seat. With this globalisation of industrial products, many problems and opportunities have risen, primarily due to inconsistent standards existing in the market. The International Standards Organisation has tried (and seem to be very successful in doing so) to standardise a minimum level of quality norms. These norms act as the foundation to implements total quality management (TQM). TQM has been identified as a philosophy of interdependent characteristics, such as customer focus, commitment, measurement, systematic support, and continuous improvement. This paper presents a case study on the implementation of ISO 9002: 1994 at Kerala Hitech Industries (KELTEC), with the benefits, hurdles faced, and shortcomings. Upgradation of KELTEC's quality management system to the requirements of ISO 9001: 2000 is currently under progress. |
| | Application of the distribution of the sum of r independent truncated Poisson variables in quality control
Author : Samarsimhudu, P. ;Singh, Naunihal
Source : Defence Science Journal ; Vol:13(1) ; 1963 ; pp 18-22
Subject : 519.2 Statistics
Keywords : Truncated poisson ;Quality control ;Poisson distribution
Abstract : This paper deals with the application of the sum of 'r' independent truncated Poisson variates, in fixing the number of defects on each of the components in a set with certain probability, when the total number of allowable defects in a set is known, so as to avoid wastage of finished product. To meet this end a few tables are prepared and appended. |
| | Closed vessel technique for assessment of ballistic characteristics in quality control of propellant manufacture
Author : Ramakrishnan, Shiva
Source : Defence Science Journal ; Vol:8(3) ; 1958 ; pp 180-200
Subject : 623.5 Armaments and Ballistics
Keywords : Vessel technique ;Ballistic ;Quality control
Abstract : "In order to assess the ballistic performance of a propellant it is necessary to measure its following characteristics: (a)Force constant, (b)vivacity, and (c)shape. It is possible to determine (a)and (b)by the closed vessel technique which enables ballistic performance of the propellant in the gun to be estimated. It can be very usefully employed for quality control of propellant manufacture. As more and more experience is gained in the closed vessel technique these tests have several other possible practical applications such as those: (a)for inspection of propellants, (b)for assessment of quality, (c) to reduce proof in guns, and (d)to check ballistics of a lot after long storage." |
| | The comparative efficiency of the X and R Charts and L-S chart for statistical quality control
Author : Iyer, P.V.Krishna ;Bhattacharyya, M.N.
Source : Defence Science Journal ; Vol:4(2) ; 1954 ; pp 55-66
Subject : 519.2 Statistics
Keywords : Quality control ;Statistics
Abstract : This paper deals with the comparative efficiencies of the X and R charts and the L-S chart (L being the largest and S the smallest value of the sample) from the theoretical and practical points of view. It has been found that in practice the corrective steps suggested by both tallied almost exactly. From theoretical points, when standard deviation varies, the L-S chart is almost as efficient as the X and R charts, but with the variation in the mean the relative efficiency of the L-S chart comes down appreciably as the X and R charts, but with the variation in the mean shifts more and more from the original value. |
| | Failure analysis of compressor blade of typical fighter class aero engine : A case study
Author : Sahoo, Benudhar ;Gouda , Gantayat
Source : Defence Science Journal ; Vol:52(4) ; 2002 ; pp 363-367
Subject : 629.7 Aeronautics
Keywords : Failure analysis ;Compressor blade ;Aero engine ;Fighter aircraft ;Rotor blade ;Stress analysis ;Quality control
Abstract : Failure of second-stage compressor rotor blade of a typical Russian fighter-class aero-engine has resulted in few accidents and many incidents. Apart from this, during manufacturing stage there was high rejection rate of this rotor blade in vibrational fatigue tests. Metallurgical investigations of the failed rotor blade reveals that the mode of failure'is fatigue. The various reasons of this fatigue crack are micro-inclusion, silica embedment and hydrogen attack. This was analysed from the three different approaches, namely, theoretical stress analysis, basic design and quality control. To contain the possibility of silica embedment and hydrogen attack, sand electro-corrundum blasting and measure-replaced blasting have been taken to control hydrogen embedment. |
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