\"What are your assumptions (implicit as well as explicit) about the most effective way to manage people?\" So began Douglas McGregor in this 1960 management classic. It was a seemingly simple question he asked, yet it led to a fundamental revolution in management. Today, with the rise of the global economy, the information revolution, and the growth of knowledge-driven work, McGregor's simple but provocative question continues to resonate-perhaps more powerfully than ever before. Heralded as one of the most important pieces of management literature ever written, a touchstone for scholars and a handbook for practitioners, The Human Side of Enterprise continues to receive the highest accolades nearly half a century after its initial publication. Influencing such major management gurus such as Peter Drucker and Warren Bennis, McGregor's revolutionary Theory Y-which contends that individuals are self-motivated and self-directed-and Theory X-in which employees must be commanded and controlled-has been widely taught in business schools, industrial relations schools, psychology departments, and professional development seminars for over four decades. In this special annotated edition of the worldwide management classic, Joel Cutcher-Gershenfeld, Senior Research Scientist in MIT's Sloan School of Management and Engineering Systems Division, shows us how today's leaders have successfully incorporated McGregor's methods into modern management styles and practices. The added quotes and commentary bring the content right into today's debates and business models. Now more than ever, the timeless wisdom of Douglas McGregor can light the path towards a management style that nurtures leadership capability, creates effective teams, ensures internal alignment, achieves high performance, and cultivates an authentic, value-driven workplace--lessons we all need to learn as we make our way in this brave new world of the 21st century.

The Human Side of Enterprise.

Project controls have traditionally been focused on after-the-fact detection of variances. This thesis proposes a control system, the Last Planner system, that causes the realization of plans, and thus supplements project management’s concern for management of contracts with the management of production.

The Last Planner system has previously been successfully applied by firms with direct responsibility for production management; e.g., specialty contractors. This thesis extends system application to those coordinating specialists, both in design and construction, through a series of case studies, one of which also explores the limits of unilateral implementation by specialists.

In addition to the extended application, two questions drive this research. The first question is 1) What can be done by way of tools provided and improved implementation of the Last Planner system of production control to increase plan reliability above the 70% PPC level? Previous research revealed substantial improvement in productivity for those who improved plan reliability to the 70% level, consequently there is reason to hope for further improvement, possibly in all performance dimensions, especially with application across an entire project rather than limited to individual specialty firms. That question is explored in three case studies, the last of which achieved the 90% target.	

The second question is 2) How/Can Last Planner be successfully applied to increase plan reliability during design processes. That question is explored in an extensive case study, which significantly contributes to understanding the design process from the perspective of active control, but unfortunately does not fully answer the question, primarily because the project was aborted prior to start of construction. However, it is argued that Last Planner is especially appropriate for design production control because of the value-generating nature of design, which renders ineffective traditional techniques such as detailed front end planning and control through after-the-fact detection of variances.

Issues for future research are proposed, including root cause analysis of plan failures and quantification of the benefits of increased plan reliability for both design and construction processes.

/pdf/the-last-planner-system-of-production-control-3b02rm1jde.pdf

The last planner system of production control

Previous research suggests that the construction industry is characterized by (1) particular complexity factors owing to industry specific uncertainties and interdependences, and (2) inefficiency of operations. The aim of this study was to analyse the operations and behaviour of firms as a means of dealing with complexity. The observations made indicate that the industry as a whole is featured as a loosely coupled system. Taking this as a starting point, the couplings among activities, resources and actors were analysed in different dimensions. The pattern of couplings builds on two interdependent layers: tight couplings in individual projects and loose couplings based on collective adaptations in the permanent network. It is concluded that the pattern of couplings seems to favour short term productivity while hampering innovation and learning.

The Construction Industry as a Loosely Coupled System - Implications for productivity and innovativity

http://impgroup.org/uploads/papers/169.pdf

The construction industry as a loosely coupled system - implications for productivity and and innovativity

The author details the reactions of various concretes on steel reinforcement. Although portland cements, slag cements and high alumina cements are all hydraulic binders, each possess special properties which are examined. The discussion of causes and methods of preventing the corrosion of steel reinforcement covers such aspects as galvanised steel reinforcement, effects of concrete composition, corrosion of steel reinforcments in concrete and prestressed reinforcement. It is concluded that the most significant influences on the corrosion of prestressing wire in concrete are: the presence of chloride; the presence of nitrates; the composition of the concrete; the degree of carbonation of the concrete; concrete compaction and, chlorides and sulphates should be used as far as possible when steel is embedded. (TRRL)

Corrosion of steel by concrete

This paper presents an experimental investigation into the residual capacity of corroded reinforcing bars. By performing both accelerated and simulated corrosion tests on bare bars and on bars embedded in concrete, the mechanism of the reduction of the capacity of corroded reinforcement was investigated. The influence of type and diameter of reinforcement on its residual capacity is discussed. The experimental results show that, due to local attack penetration, the residual cross-section of a corroded bar is no longer round and varies considerably along its circumference and its length. Although the force–extension curves of corroded bars are similar to those of non-corroded bars for up to 16% corrosion, their residual yield and ultimate forces decrease more rapidly than their average cross-sectional area and, therefore, their residual strength decreases significantly. Even though the residual capacity of corroded small diameter and/or plain bars reduces more than that of large diameter or ribbed ones, di...

/pdf/residual-capacity-of-corroded-reinforcing-bars-1844vpo7pa.pdf

Residual capacity of corroded reinforcing bars

An experimental investigation into the effect of corrosion on the ductility of steel reinforcement is reported. Both accelerated and simulated corrosion tests were conducted on bare bars and on bars embedded in concrete. The mechanism and degree of the reduction of ductility of reinforcement due to corrosion were examined. The influence of bar type and diameter on ductility of corroded reinforcement is discussed. The experimental results indicate that, since local attack penetration results in a significant variation of residual cross-section along its length, corrosion significantly reduces ductility of reinforcement. Although the strength ratio, elastic modulus and hardening strain only vary with bar type rather than corrosion level, the elongation, ultimate strain and ductile area of corroded reinforcement reduce much more significantly than do those of their yield and ultimate strengths. There is concern regarding bar ductility since about 10% corrosion may possibly decrease the ultimate strain of reinforcement below the minimum requirement specified in CEB Model Code 90 for class S reinforcement. Even though the elongation, ultimate strength and ductile area parameter of corroded small diameter and/or plain bars reduce more than those of large diameter and/or ribbed ones, such differences are not significant and can be neglected. Finally, a set of simple empirical equations is proposed to assess the ductility of corroded reinforcement in practice.

/pdf/effect-of-corrosion-on-ductility-of-reinforcing-bars-4i6ih0519k.pdf

Effect of corrosion on ductility of reinforcing bars

Finite element analysis of the effects of radial expansion of corroded reinforcement

This paper reports an experimental study of concrete beams with corroded reinforcement to investigate their failure modes and ductility behavior. Before the beams were simply supported and monotonically loaded to failure, they were subjected to a process of electrochemically accelerated corrosion. The experimental results show that, in addition to reducing beam flexural strength, corrosion alters its failure modes and affects its ductile behavior substantially. When the response of a beam is dominated by cracking of its compression concrete and/or the reduction of its tension bar area, corrosion improves beam ductility. When the behavior of a beam is controlled by deterioration of its bond strength and/or the reduction of its steel ductility, however, corrosion decreases beam ductility. This raises a concern regarding the ductility of commonly used under-reinforced beams if the amount of corrosion exceeds approximately 10% because the beam could fail suddenly by the rupture of its corroded tension reinforcement due to the ultimate strain of the latter being reduced considerably.

Impact of Reinforcement Corrosion on Ductile Behavior of Reinforced Concrete Beams

Tests were carried out to investigate the magnitude of pressure created by corrosion products on steel in reinforced concrete that would cause surface cracking of the concrete cover. Test specimens were 150 mm cubes with 8 mm or 16 mm holes provided at various locations and formed by reinforcing bars. The cracking resistance of cover concrete was measured experimentally by pressurizing the holes, and an attempt was made at its prediction using plastic methods of analysis. Experimental failure pressures were found to be influenced by cover/bar diameter ratio, aggregate size, bar diameter, and bar location. The observed lack of correlation between tensile strength and failure pressure lends support to the suggestion made by other researchers that a fracture mechanics approach may be more appropriate. This suggestion was supported by an unsuccessful attempt to find a relationship between cover thickness and effective plastic strength.

L. A. Clark

Papers

Residual capacity of corroded reinforcing bars

Effect of corrosion on ductility of reinforcing bars

Finite element analysis of the effects of radial expansion of corroded reinforcement

Impact of Reinforcement Corrosion on Ductile Behavior of Reinforced Concrete Beams

Pressure required to cause cover cracking of concrete due to reinforcement corrosion