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Article
Publication date: 1 January 1998

R.C. EVANS and A.P. KAKA

Several cash flow forecasting models have been developed for use by the contractor at the tendering stage. The majority of these models have been based on the standard…

Abstract

Several cash flow forecasting models have been developed for use by the contractor at the tendering stage. The majority of these models have been based on the standard S‐curve. The accuracy of these models depends on the accuracy of the standard S‐curve used. Many researchers have attempted to develop standard S‐curves using past projects. These projects were primarily classified in terms of broad‐based categories (e.g. commercial buildings). The results of past research have demonstrated that cumulative value/cost curves vary significantly. In the present paper, a more specific type of building was selected (food retail stores). Historical data for 20 projects was collected and analysed for the feasibility of developing a more accurate standard S‐curve. The results demonstrate that an accurate standard S‐curve was not achieved even when projects were further classified into more detailed groups (i.e. different sizes of superstores).

Details

Engineering, Construction and Architectural Management, vol. 5 no. 1
Type: Research Article
ISSN: 0969-9988

Keywords

Article
Publication date: 21 May 2020

Osman Hürol Türkakın, Ekrem Manisalı and David Arditi

In smaller projects with limited resources, schedule updates are often not performed. In these situations, traditional delay analysis methods cannot be used as they all…

Abstract

Purpose

In smaller projects with limited resources, schedule updates are often not performed. In these situations, traditional delay analysis methods cannot be used as they all require updated schedules. The objective of this study is to develop a model that performs delay analysis by using only an as-planned schedule and the expense records kept on site.

Design/methodology/approach

This study starts out by developing an approach that estimates activity duration ranges in a network schedule by using as-planned and as-built s-curves. Monte Carlo simulation is performed to generate candidate as-built schedules using these activity duration ranges. If necessary, the duration ranges are refined by a follow-up procedure that systematically relaxes the ranges and develops new as-built schedules. The candidate schedule that has the closest s-curve to the actual s-curve is considered to be the most realistic as-built schedule. Finally, the as-planned vs. as-built delay analysis method is performed to determine which activity(ies) caused project delay. This process is automated using Matlab. A test case is used to demonstrate that the proposed automated method can work well.

Findings

The automated process developed in this study has the capability to develop activity duration ranges, perform Monte Carlo simulation, generate a large number of candidate as-built schedules, build s-curves for each of the candidate schedules and identify the most realistic one that has an s-curve that is closest to the actual as-built s-curve. The test case confirmed that the proposed automated system works well as it resulted in an as-built schedule that has an s-curve that is identical to the actual as-built s-curve. To develop an as-built schedule using this method is a reasonable way to make a case in or out of a court of law.

Research limitations/implications

Practitioners specifying activity ranges to perform Monte Carlo simulation can be characterized as subjective and perhaps arbitrary. To minimize the effects of this limitation, this study proposes a method that determines duration ranges by comparing as-built and as-planned cash-flows, and then by systematically modifying the search space. Another limitation is the assumption that the precedence logic in the as-planned network remains the same throughout construction. Since updated schedules are not available in the scenario considered in this study, and since in small projects the logic relationships are fairly stable over the short project duration, the assumption of a stable logic throughout construction may be reasonable, but this issue needs to be explored further in future research.

Practical implications

Delays are common in construction projects regardless of the size of the project. The critical path method (CPM) schedules of many smaller projects, especially in developing countries, are not updated during construction. In case updated schedules are not available, the method presented in this paper represents an automated, practical and easy-to-use tool that allows parties to a contract to perform delay analysis with only an as-planned schedule and the expense logs kept on site.

Originality/value

Since an as-built schedule cannot be built without updated schedules, and since the absence of an as-built schedule precludes the use of any delay analysis method that is acceptable in courts of law, using the method presented in this paper may very well be the only solution to the problem.

Details

Engineering, Construction and Architectural Management, vol. 27 no. 10
Type: Research Article
ISSN: 0969-9988

Keywords

Article
Publication date: 12 May 2021

Qian Long Kweh, Wen-Min Lu, Irene Wei Kiong Ting and Hanh Thi My Le

First, this study assesses firms’ efficiency of transforming intellectual capital (IC) components into firm performance. Second, this study examines (1) cubic S-curve

Abstract

Purpose

First, this study assesses firms’ efficiency of transforming intellectual capital (IC) components into firm performance. Second, this study examines (1) cubic S-curve relationship between board independence and IC efficiency and (2) how firm size moderates the cubic S-curve relationship.

Design/methodology/approach

This study employs a stochastic nonparametric envelopment of data (StoNED) framework to estimate IC efficiency, which is derived from the estimation process of transforming structural, relational and human capitals into accounting- and market-based performance indicators. This study conducts regression analyses on 1,104 firm-year observations of Taiwanese semiconductor firms over the period of 2011–2018.

Findings

StoNED results suggest that sample firms' IC efficiency can be relatively improved by approximately 80%. Regression results indicate that a cubic S-curve relationship between board independence and IC efficiency exists, and firm size moderates the nonlinear effects.

Practical implications

Overall, this study highlights the importance of examining the nonlinear effect of board independence on IC efficiency from the perspective of agency theory, and the moderating effect from firm size, which may suggest availability of resources from the resource-based view of the firm.

Originality/value

This study contributes to the literature through the innovative application of an efficiency-based tool for evaluating IC efficiency. The cubic S-curve relationship between board independence and IC efficiency also points to the policy concerning the appropriate number of independent directors on board.

Details

Journal of Intellectual Capital, vol. 23 no. 5
Type: Research Article
ISSN: 1469-1930

Keywords

Article
Publication date: 1 January 1996

AMMAR P. KAKA and FARZAD KHOSROWSHAHI

This paper addresses the effect of different procurement methods (traditional, design and build and management contracting) on project cash flow. Historical data relating…

Abstract

This paper addresses the effect of different procurement methods (traditional, design and build and management contracting) on project cash flow. Historical data relating to the periodic cost of 150 construction projects were collected. Four criteria were identified to classify the projects: type of project, size, company and type of procurement. The effect of these criteria on the S‐curves was then examined using ANOVA. Results confirmed that differently procured projects with different sizes produce different patterns. The company and type of project did not significantly affect the shape of the S‐curve. Standard S‐curves were then modelled for the three aforementioned procurement routes. These curves were used to calculate the relevant cash flows using a computer based cash flow forecasting model. A series of simulation tests were conducted to evaluate the extent of variation in cash flow, given different contract conditions. Results revealed that, in some cases, the variation in procurement routes has a significant effect on contract cash flows.

Details

Engineering, Construction and Architectural Management, vol. 3 no. 1/2
Type: Research Article
ISSN: 0969-9988

Keywords

Article
Publication date: 3 February 2012

Mohsen Bahmani‐Oskooee and Dan Xi

Impact of currency depreciation or devaluation on the trade balance is not instantaneous. Indeed, because of adjustment lags favorable effects of depreciation is only…

Abstract

Purpose

Impact of currency depreciation or devaluation on the trade balance is not instantaneous. Indeed, because of adjustment lags favorable effects of depreciation is only realized in the future. This short‐run dynamics of the trade balance is summarized by the S‐Curve phenomenon. The purpose of this paper is to test this phenomenon by using commodity level data between China and Germany.

Design/methodology/approach

The methodology is based on cross‐correlation function.

Findings

Out of 62 industries studied, only 22 support the S‐Curve or enjoy improvement in their trade balance in the future. The list included small and large industries as well as durable and non‐durable goods.

Originality/value

No study in the literature has considered commodity level trade between China and Germany.

Details

Journal of Chinese Economic and Foreign Trade Studies, vol. 5 no. 1
Type: Research Article
ISSN: 1754-4408

Keywords

Article
Publication date: 1 February 1986

J.A.F. Nicholls

Both the Product Life Cycle (PLC) and a new version, the Product Evolutionary Cycle (PEC), are more than just descriptive marketing tools based on historical sales data…

Abstract

Both the Product Life Cycle (PLC) and a new version, the Product Evolutionary Cycle (PEC), are more than just descriptive marketing tools based on historical sales data. Rather, they represent dynamic instruments to enable an entrepreneur‐or coporate manager‐to estimate market development. The S‐curve, the growth part of the PLC and the PEC, makes it possible for an entrepreneur to time capital requirements, labor force recruitment, promotional efforts, distribution channels, target markets, and pricing. In the case of new products, research can be utilized to construct an S‐curve in advance of an innovation's introduction in the market‐place. Such information is invaluable to an entrepreneur, since it serves as a guide to future market development.

Details

Journal of Consumer Marketing, vol. 3 no. 2
Type: Research Article
ISSN: 0736-3761

Article
Publication date: 1 January 2006

Karl Blyth and Ammar Kaka

Cash flow forecasting is an indispensable tool for construction companies, and is essential for the survival of any contractor at all stages of the work. A simple and fast…

2531

Abstract

Purpose

Cash flow forecasting is an indispensable tool for construction companies, and is essential for the survival of any contractor at all stages of the work. A simple and fast technique of forecasting cash flow accurately is required, considering the short time available and the associated cost. Seeks to examine this issue.

Design/methodology/approach

The paper argues that instead of producing an S‐curve that is based on historical projects combined (state‐of‐the‐art is based on classifying projects into groups and producing a standard curve for each group simply by fitting one curve into the historical data), here the attempt is to produce an individual S‐curve for an individual project. A sample of data from 50 projects was collected and 20 criteria were identified to classify these projects. Using the most influential criteria, a multiple linear regression model was created to forecast the programme of works and hence the S‐curves. A further six projects were used to validate and test the model.

Findings

The results of the model developed in this paper were compared with previous models and evaluated. It is concluded that the model produced more accurate results than existing value and cost models.

Originality/value

The paper proposes an alternative and novel approach to the development of standard value and cost commitment S‐curves. This approach is based on a multiple linear regression model of the programmes of works.

Details

Engineering, Construction and Architectural Management, vol. 13 no. 1
Type: Research Article
ISSN: 0969-9988

Keywords

Article
Publication date: 2 November 2010

Mohsen Bahmani‐Oskooee and Scott W. Hegerty

Since the introduction of the concepts of the J‐ and S‐curves, many researchers have tried to verify their validity empirically. This paper aims to review the related…

2025

Abstract

Purpose

Since the introduction of the concepts of the J‐ and S‐curves, many researchers have tried to verify their validity empirically. This paper aims to review the related papers and to offer direction for future research.

Design/methodology/approach

This is a review paper. As such, no method is employed here. Rather, the methodologies used by others to test the J‐ and S‐curves are explained and reviewed.

Findings

No new findings are offered since this is a review paper.

Practical implications

The J‐ and S‐curves show whether currency depreciation worsens the trade balance first before improving it. Since the majority of studies are country‐specific, policymakers could benefit by learning whether currency depreciation will be effective in improving the trade balance.

Originality/value

This is a literature review paper and its originality is in terms of collecting the literature together and presenting it in one single paper.

Details

Journal of Economic Studies, vol. 37 no. 6
Type: Research Article
ISSN: 0144-3585

Keywords

Article
Publication date: 13 August 2018

Chongxu Liu and Youdong Chen

The glass substrate transfer robot uses flexible arm and fork to transport the glass substrate which will generate vibration. To reduce the settling time and increase…

Abstract

Purpose

The glass substrate transfer robot uses flexible arm and fork to transport the glass substrate which will generate vibration. To reduce the settling time and increase productivity, the authors proposed a vibration suppression method that integrated the continuous input shaping into the S-curve feedrate profiling.

Design/methodology/approach

The quasi-optimal S-curve feedrate profiling is achieved by the robot model. Then the outputs of the S-curve are shaped by the continuous input shaper, which can greatly lower the vibration and shorten the settling time.

Findings

The robot produces vibrations because of the flexibility of the belt system and the forks; the vibration of the robot is especially obvious in the acceleration and deceleration stage and the low-speed operation stage. Because the fork fingers are flexible, vibration at the end of the fork is enlarged.

Originality/value

The effectiveness of the proposed method is verified by the comparative experiments conducted on a glass substrate transfer robot.

Details

Industrial Robot: An International Journal, vol. 45 no. 4
Type: Research Article
ISSN: 0143-991X

Keywords

Article
Publication date: 1 February 2003

A.P. Kaka, J. Lewis and H. Petros

Standard value/cost flow models (often referred to as S‐curves) are widely used in cash flow forecasting, particularly at the tender stage. A substantial amount of…

1744

Abstract

Standard value/cost flow models (often referred to as S‐curves) are widely used in cash flow forecasting, particularly at the tender stage. A substantial amount of research has concentrated on improving the accuracy of these curves. Categorizing construction projects into groups and subgroups has helped, but the fact remains that different construction projects possess different profiles of cost flow. This paper is an attempt at assessing the extent of influence of planning and programming the work on the cost flow curves. One real project was used as a case study and four planners were independently asked to produce programmes for executing the project. These programmes were analysed and converted to cost flow curves using one database of productivity and unit cost rates. Results confirmed that the variations in programmes produced less variations in cost flow curves than the errors to be expected from the use of average curves derived from project groups (mean SDY 2.88 compared to previous studies of 5.5, 8.5 and 10.67). The results suggest, taking due account of the limitations of the scope of the study, that further effort at the categorisation of projects into subgroups will result in a reasonable improvement in accuracy.

Details

Engineering, Construction and Architectural Management, vol. 10 no. 1
Type: Research Article
ISSN: 0969-9988

Keywords

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