Recuentos de aerobios mesófilos

In this section the third sub-question of Phase 1 is answered:

1.3 What are the characteristics of a construction supply chain?

Supply chains can be found all around us and in various disciplines. The supply chains in the food industry are different from the supply chain of a mobile phone manufacturer and requires focus on different aspect. The same goes for the construction industry being different from others. The construction industry is viewed as a sector of the economy that transforms various resources into constructed facilities [72, p. 2]. One in three truck movement has a construction site as destination having a large impact on the total traffic congestion on the Dutch roads [51, p. 5]. Construction work starts early in the morning and the goods necessary have to be available at that time. This results in a convergence of transports in the morning and many transports stuck in traffic jams. The cost of materials in a typical construction project can take up to 60% of the total construction costs [98, p. 394]; [92, p. 73]. Material supply is an important process of construction companies and a factor affecting the quality of construction projects [94, p. 3]. In a general construction project the logistics costs may be as high as 10% of the total construction costs [15, p. 33].

In Figure 12 on the next page, the general construction supply chain setup is presented that consists of [16, p. 403]; [21, p. 325]; [108, p. 458]:

 the manufacturing of construction

goods;

 the physical distribution of goods and

transport of employees;

 the processing of goods on the

The construction goods and transport of employees need to be distributed to the construction site. In Figure 12, the two basic distribution strategies are presented:

 direct distribution of materials from manufacturer to the construction site;

 indirect distribution through intermediary companies such as wholesalers and traders.

Direct distribution is mainly used when a customer requires a Full Truck Load (FTL) of materials requiring transports with high percentage of capacity usage. In case of indirect distribution finished goods are stocked at one or more points in the supply chain [108, p. 458]. The requirement for transport between facilities in the supply chain is determined by the inventory policy followed by the CCs in the network [16, p. 220].

Typical characteristics of the construction supply chain are [40, p. 287]: [107, p. 217]; [99, p. 6]:

1. Uniqueness of construction projects;

2. Realization on the location of use;

3. Fragmented character of the construction process.

Further elaborated:

1. Traditionally, each construction project is regarded more or less in isolation such that the physical distribution streams take place by a different coalition of CCs consisting of manufacturers, LPCs such as transport and warehousing companies and contractors making every construction project unique [107, p. 217]. While each project is different, all projects are approached conservatively in process terms due to the long and entrenched traditions [112, p. 108]. A general construction project starts with the planning phase, followed by the design, construction and operation phases [32, p. 145]. The CCs are involved in storing and moving both goods and transport of employees to the construction site [40, p. 287].

2. In the automotive industry a car is constructed in a factory however the usage of the car is outside the factory. The first-tier physical distribution of goods and transport of employees have the same destination, the factory, over and over again. In the construction industry the construction site and the different routes that are used by the various CCs for the first-tier physical distribution streams, from the place of origin to the construction site, change with each new project due to the realization of the construction projects on the location of use. Contractors taking part in a construction project are responsible for their individual supply chains to provide goods and transport of employees required within their scope of work [87, p. 2]. The usage of the constructed project is on the place of realization.

FIGURE 12: PHYSICAL DISTRIBUTION STREAMS IN THE SUPPLY CHAIN OF A CONSTRUCTION PROJECT.

Manufacturer

Intermediary

company

Construction site

Indirect Indirect

3. The construction industry is highly fragmented which can have a significant negative impact, such as low productivity, cost and time overrun, conflicts and disputes resulting in claims and time consuming litigation [99, p. 6]. There is evidence, that up to 40% of the overall project duration from the inception to completion is spend on non-value-adding activities such as waiting, ordering and delivery of materials [73, p. 380]. Because they add no value to the final product and are time consuming and expensive, these non-value adding activities should be reduced to a minimum [87, p. 75]. The activities in the supply chain for the physical distribution streams of goods and transport of employees are an example of such non-value-adding activities that should be optimised to minimise the costs.

These typical characteristics of a construction project supply chain and the traditional relationships in supply and demand have undergone a variety of radical changes in recent years [24, p. 96]. There are two views in the construction industry to manage a construction project [87, p. 75]:

 Conversion view. Each stage of production is controlled independently.

 Flow view. The focus is on the control of the total flow of the production.

The traditional view is based on a conversion view on production, however, more and more, the flow view is implemented in the day to day management of construction projects. Each phase of construction involves a variety of suppliers and subcontractors who contribute to the production with a possible multiplicity of goods delivered and transports of employees. Construction activities, in general, are divided into sequential activities, which are given to different specialists for execution, putting unnecessary constraints on the work flow, increasing the possibility of conflicts and consequently leading to time waste and rework [57].

During construction important actors are [33, p. 157]:

 main contractor;  subcontractors;  purchasers;  project manager;  material suppliers;  equipment suppliers;  designers;  financial institutions;  insurance agencies;  regulatory bodies.

The construction procurement system evolves and traditional systems such as general contracting in which subcontractors are hired to perform activities in the construction process are often replaced by Performance Management (PM) systems, where the manager acting on behalf of the employer decides on designer, contractor and supplier selection. The choice of materials, their manufacturers or even supplier belongs no longer to the designer or the contractor, but to the employer or his consultant or project manager [96, p. 151]. All having their effects on the physical distribution streams in the supply chain of construction projects. Challenges in the construction industry are [34, p. 587]:

1. The difficulty of capturing, structuring, prioritizing and implementing client’s needs.

2. The dispersed design, fabrication and construction data making it difficult to convey the data

to the downstream.

3. The lack of integration, co-ordination and collaboration between various disciplines during

4. The poor communication of design intention and rationale resulting in unwarranted design changes, inadequate design specifications, unnecessary liability claims, and the increase of project time and costs.

These challenges should be at the core of attention of managers that are optimising supply chains in the construction industry. Dissatisfaction with the fragmented and temporary organisation of the construction supply chain has led several companies to offer a total construction package from design to delivery of a construction project including maintenance and exploitation. This reduced project uncertainty, by systemisation and integration of the different stages of the building process [108, p. 457].

In this section the setup and characteristics of a construction supply chain were set out in order to gain a better understanding of the supply chain in the HWC projects. In the next section the results of the ABC analysis conducted on the mapping of the case study project are elaborated upon.