LEAN CONSTRUCTION

The Design of Material Delivery System Based on Lean Construction



Table of Contents

Basic Features of Construction Logistics3

Changes and Patterns of Supply Systems in Construction5

Delivery Systems and Logistics Systems of Construction Projects10

Summary10

The Design of Material Delivery System Based on Lean Construction

Introduction

The tendencies towards efficiency improvement and risk control in project management indicate the significance of logistics, i.e. a branch of knowledge applying new concepts to control material, service, and information and finance flows between suppliers and customers. In the field of construction, procurement planning and execution (ordering, reception, transport and storage) dominates the logistic processes.

The paper focuses on a number of aspects of logistics and its specific features regarding a construction company as an organization and as a participant in a construction project. The results of a ten-year survey of changes of construction supply systems are presented and analyzed in relation to the project delivery system as a premise for the selection of the supply system. The enclosed simulation-based calculations of logistics expenses present the impact of supply organization on costs.

Basic Features of Construction Logistics

Logistics is often defined as managing the supply chains, the latter being a network of organizations linked by material and information flows bounded with a product (project) life cycle (from the procurement of raw materials through processing and handling the products and the final product, distribution and sales to the end-user and finally, to waste utilization). All the processes and relations concerning the above flows form a logistic system. A company, being a member of a larger supply chain of suppliers and customers, has its own system of internal logistics also in the form of supply chains (Fig.1)

Fig. 1. A building contractor within a supply chain of materials and participants of a project

Logistic processes are present in various fields of activity within a company (purchase, production, sale etc.). Isolating and integrating logistic tasks performed by all organizational units of a company results in creating logistics departments that co-ordinate all the flows. Three basic models of logistic systems are to be observed in building companies:

informal, where co-ordination of logistic tasks of separate departments and fields of activity is enforced within the existing organizational structure of the company,

semiformal, where a logistics manager takes the responsibility for the coordination of logistic processes of the company, but is not in charge of the departments, where these processes are conducted,

Formal, where a separate department takes over all the logistic processes of the company.

The particular model of logistics is selected according to the current organization structure of the company, its targets and management strategy. The actual size of company is also important. 97% of all Polish contractors employ up to 20 people and, therefore, have no logistics department in their structure.

Contractors are usually only single links of logistic chains that provide a project with products, services, information and finance. In contrast to manufacturing industries, which profit with long-lasting partnership with suppliers and customers, logistic chains in construction are considerably more difficult to manage and to ...