Hamza Farooq Gabriel

Six Sigma in construction: a review of critical success factors

Purpose This paper aims at collecting and reviewing the published literature on the Six Sigma in construction along with its critical success factors (CSFs). Design/methodology/approach The research is based on literature review. Based on the keyword and semantic search techniques, papers published on the topic of Six Sigma during 2000-2015 are retrieved. Frequency analysis is performed to find out significance of identified CSFs, and zoning is performed based on the product of frequency of appearance and parties affected by the CSFs. Findings A total of 69 CSFs are identified as published in the literature. Based on an inclusion criterion of minimum 15 appearances, 22 CSFs are shortlisted for further analysis. Of these CSFs, around 32 per cent fall into red zone (most critical), 50 per cent into yellow and 18 per cent into green zone (least critical). Research limitations/implications This work is limited by partial identification of CSFs. Though based on an extensive search, the retrieved CSFs may not be all the published ones. However, more thorough search techniques can be applied to improve upon this work. Practical implications The findings can be used to facilitate the decision-making in the context of project success. Originality/value This work is an original attempt at gathering Six Sigma CSFs applicable to construction projects. It may be used for further research and development to help ensure project quality and success.

The Influence of Conceptual Flow Simulation Model Parameters on Model Solution

This article investigates the influence of conceptual flow simulation model parameters (i.e coefficients and constants that need to be estimated in calibration) on model solution (surface runoff) to understand the characteristics of the model. A new conceptual watershed yield model (WYM) was employed. There are four physical parameters, two fitting coefficients and two initial estimates of the surface water and groundwater storagesthat control the functioning of the model. The conceptual model was applied on Ling River near Kahuta and detailed sensitivity analysis was performed to explore the most sensitive model parameters. The most sensitive model parameters worked out were Cg (a fitting coefficient, which reflects the rate at whichgroundwater runoff occurs), wr (watershed retention is the initial rainfall losses before runoff begins), pgr (inputparameter that reflects the discharge capacity of the groundwateraquifer). The model parameters like ic (infiltration coefficient), gwsm (input parameter that depends on the subsurface storage available in the watershed) and ep (input parameter) have negligible effect on model solution. It was observed that wr (watershed retention) is the only surface runoff controlling parameter and pgr and Cg are the groundwater runoff controlling parameters.

Studying Impact of Climate Change on Wheat Yield by Using DSSAT and GIS: A Case Study of Pothwar Region

Today global climate change and its impact on crop production is a major issue. Climatic factor such as temperature has been closely linked to agricultural production. According to the international panel on climate change (IPCC) these changes are very rapidly affecting crop productivity. To explore the future climate change impacts on wheat yield in Pakistan, especially the rain fed region of Pothwar which is considered vulnerable to climate change, a wheat crop simulation study was conducted. The specific objectives of the study were to (a) simulate the impact of climate change using DSSAT on wheat yield in the Pothwar region using IPCC climate change scenario for Pakistan and (b) generate spatial maps of wheat yield and correlate with climatic factors. The crop simulation study assessed the impact of rise in maximum and minimum Temperature on the wheat yield. The CERES-Wheat which is a component of the Decision Support System for Agrotechnology Transfer (DSSAT) model was used to input soil, crop management practices and weather data. IPCC Fourth Assessment report B1 scenario for increasing temperature was used in the simulations. The simulated results were imported into ArcGIS to produce regional impact maps for visual assessment and spatial analysis under different climate change scenarios levels through an interface of ArcMap. The DSSAT model simulated results showed that the rise in maximum and minimum temperature decreased the wheat yields across the Pothwar region. The similar methodology could be adopted for different crops in other parts of the country for better mitigation of future food security.

Empirical Evidence of Extension of Time in Construction Projects

AbstractAlmost all construction projects face delays resulting in extension of time (EOT) or liquidated damages, depending upon which of the two parties absorbs the responsibility as per terms of t...

Seismic Vulnerability Assessment of Deficient RC Structures with Bar Pullout and Joint Shear Degradation

Pakistan is an underdeveloped country, still striving for improvement in construction practices. Most of the private construction is carried out as nonengineered which caused loss of approximately 85,000 lives in Kashmir (2005) earthquake. However, after the Kashmir (2005) earthquake, the government and engineering community emphasized on implementation of seismic codes. Although the current construction practices are considered as better than previous construction work the vulnerability of these structures is yet to be determined. It aims at the vulnerability assessment of recent RC construction in Pakistan that still needs to be assessed. Research work starts with calibration of panel zone element (PERFORM 3D) depicting joint shear degradation, while comparing the analytical results with experimental work, found in the literature. The frame work is then used for vulnerability assessment of RC structures typical of current construction practices in Pakistan while using advanced capacity spectrum method, developed by Kyriakides for which three cases have been considered, being constructed more frequently by public sector, in different seismic zones, based on design usually followed by builders in the region. Finally, the conclusion is drawn with suggestion of further improvement of seismic behavior of the structures.

THE INFLUENCE OF MODEL PARAMETERS ON CATCHMENT RESPONSE

This paper deals with the study of influence of conceptual rainfall-runoff model parameters on catchment response. A lumped conceptual watershed yield model, based on pragmatic approach, is employed to study the influence of model parameters on catchment response i.e runoff. The model is calibrated using manual parameter fitting approach also known as trial and error parameter fitting. In all, there are parameters that control the functioning of the model. The detailed analysis was performed on Ling River near Kahuta having catchment area of 145.04 sq. km. (56 sq. miles). The model includes physical parameters linked with groundwater storage, evapotranspiration and coefficients of infiltration & groundwater storage, and initial estimates of the surface water and groundwater storages. As sensitivity analysis is a very useful tool for parameter optimization therefore, it was performed to evaluate the influence of model parameters on runoff. The sensitivity and relative contributions of model parameters influencing catchment response are studied. The analysis confirmed that model parameters linked with surface runoff parameters specified for each month are more significant as compared to infiltration, evapotranspiration and subsurface input parameters.

A SIMPLE CONCEPTUAL MODEL TO COMPUTE WATERSHED YIELD IN HUMID REGIONS

A new conceptual model has been formulated with simple structure and computational algorithm to compute watershed yield on monthly basis from rainfall as input for humid regions. It is applicable to the watersheds having areas less than 3930 Km 2 . In all, there are twenty parameters that control the functioning of the model. The conceptual model is restricted to two storage elements or units (surface water storage and groundwater storage) having simple hydrologic characteristics. The model has been successfully applied and calibrated on four sample watersheds of Pakistan. A lumped parametric approach has been used. The model also used the data other than that employed in the calibration to test the accuracy or predictive capability of the model on tested data, quite reasonable results were obtained, therefore model could be considered for application to other watershed having similar hydrometeorological conditions.