Improvement of product development cycle time and cost by applying concurrent integrated design and assembly planning : executive summary

Sonca is a manufacturing operation producing torches and lanterns. In order for the Company to be competitive, one of the key factors is to introduce new products to market quicker and at a lower total product cost. A system titled "concurrent integrated design and assembly planning (CIDAP)" is developed to aid this process. It is identified that methods proposed by other researchers using different algorithms are not interactive enough and need too much space to store the representation of assembly sequences and time to process the assembly operations for a complex assembly. Besides, the commercially available systems and software are not integrated and are too universal. The data used is not compatible with the company's data file. The CIDAP framework focuses on concurrent and integration, in that the different processes in the whole product development cycle are carried out concurrently and are integrated. In the framework two techniques, namely KALG (Knowledge-based Assembly Liaison Graph) and KPN (Knowledge-based Petri Net) and four expert systems for selection of assembly system, feeder, gripper, and sensing technology are developed. Commercially available software such as Boothroyd and Dewhurst's DFMA (Design For Manufacture and Assembly) software, Rapid Prototyping and Quick Tooling are also applied in the framework. The frame work and the systems are applied to an actual case in designing a series of torches within the Company. Results show that the product development cycle time is improved by 25%, rework cost reduced by 20%, and final product cost reduced by 11 %. The Company has adopted the new framework. The developed systems and data files are not only applicable to the Company, but also to other small and medium size companies in Hong Kong and China with a similar scale and nature of operation

Performance variation and job enrichment in manual assembly work

published_or_final_versionIndustrial EngineeringMasterMaster of Science in Engineerin

Microwave synthesis of colloidal stable AlPO-5 nanocrystals with high water adsorption capacity and unique morphology

International audienc

AlPO-5 nanocrystals templated by 1-ethyl-2,3-dimethylimidazolium hydroxide and their textural and water sorption properties

International audienc

Development and validation of risk prediction models for COVID-19 positivity in a hospital setting

ObjectivesTo develop: (1) two validated risk prediction models for coronavirus disease-2019 (COVID-19) positivity using readily available parameters in a general hospital setting; (2) nomograms and probabilities to allow clinical utilisation.MethodsPatients with and without COVID-19 were included from 4 Hong Kong hospitals. The database was randomly split into 2:1: for model development database (n = 895) and validation database (n = 435). Multivariable logistic regression was utilised for model creation and validated with the Hosmer-Lemeshow (H-L) test and calibration plot. Nomograms and probabilities set at 0.1, 0.2, 0.4 and 0.6 were calculated to determine sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV).ResultsA total of 1330 patients (mean age 58.2 ± 24.5 years; 50.7% males; 296 COVID-19 positive) were recruited. The first prediction model developed had age, total white blood cell count, chest x-ray appearances and contact history as significant predictors (AUC = 0.911 [CI = 0.880-0.941]). The second model developed has the same variables except contact history (AUC = 0.880 [CI = 0.844-0.916]). Both were externally validated on the H-L test (p = 0.781 and 0.155, respectively) and calibration plot. Models were converted to nomograms. Lower probabilities give higher sensitivity and NPV; higher probabilities give higher specificity and PPV.ConclusionTwo simple-to-use validated nomograms were developed with excellent AUCs based on readily available parameters and can be considered for clinical utilisation