Case Studies in Maintenance and Reliability: A Wealth of Best Practices. V. Narayan

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СКАЧАТЬ spark plugs was also rising rapidly. As a result, the company’s own production process needed additional factory area. The company decided to relocate the SPM division to a new factory to be built on a green-field site. This would release an additional 60,000 square feet in the existing plot to cater to the growth in primary product demand.

      They owned a plot adjacent to the existing factory, with a public road dividing them. The plan was to build a new factory building 100,000 square feet in area with its own infrastructure services such as electricity supply, water, and air. The SPM division would thereafter operate as a profit center.

      For many years, the company had used a respectable and reliable firm of architects for their civil engineering work. At the time of these events, they were supervising the extension of an existing factory building (described briefly in Chapter 22). While observing this work, I noticed that our own civil engineers and the architects were operating well within their comfort zones.

      The architect’s designs looked very sound, but it was not clear whether more economic designs were feasible. We could resolve this question by opening the architectural and structural design work to outside bids. After obtaining approval to conduct a conceptual design competition, we invited other qualified architects. The successful submission would meet specified criteria: customer expectations, cost, and adherence to schedule.

      4.2 Customer Expectations

      In Chapter 3, we discussed the importance of getting the inputs of shop-floor staff when planning for the future. We applied this principle in planning this project. The starting point was ‘market research’ with our main customers, the workers in the SPM division.

      We prepared a questionnaire to evaluate the requirements and expectations of all the people who would be working in the new factory building. The questions tried to identify their preferences with regard to working conditions and services. Specific requirements of specialized groups could be recorded in free text. We selected about 50 machinists and assembly technicians randomly, then interviewed them individually, using the questionnaire as a prompt. We interviewed trade union representatives, designers, and managers as well. The results were compiled and collated so that we had a good idea of the expectations of a cross-section of customers.

      As in the earlier exercise described in Chapter 3, we were quite surprised at the number of common factors in their responses. The majority of those interviewed wanted the following:

      1.Natural ventilation; in the existing factory, large column-mounted air circulators were used to cool the work area; they did not want these in the new building.

      2.Natural lighting.

      3.Large spans between columns; some people specified 60–70 feet as the desired span in both directions.

      4.Overhead gantry cranes to cover the entire assembly and dispatch bays.

      5.At least 20 cubic feet of storage space per machine-tool, for tools, jigs, and fixtures.

      6.Dry air supply for machines; in the existing factory buildings, condensed water in the air pipelines had been a major problem for some years.

      7.Assured supply of power and water.

      There were a few other requirements, but these were relatively minor and could be carried out at low cost during the detailed design.

      4.3 Technical Criteria

      In the earlier designs of the factory buildings, north light trusses were used. At the time this project was being planned, structural and reinforcement steels were very expensive and in short supply in the country. As a result, the roof structure costs were over 30% of the total whereas the foundation costs were relatively low, because the site was on a solid granite formation. In the most recent design, the weight of the roof structure was about 6.8 lbs/square foot of roof area; in earlier designs, it was nearly 7.5 lbs/sq ft. We decided to inform the participants in the competition that we would expect to see a significant improvement in the structural design over the current performance.

      We told them of our desire for large spans, cranes, and other items highlighted in the survey results.

      4.4 Commercial Terms

      We paid a nominal fee to the competitors to cover part of the costs of preparing their proposals. Under the terms of the competition, they had to assign the ownership of their designs to the company. The company could ask the winning competitor to incorporate features from other designs if that was considered useful.

      The competitors were to advise us of their fee structure, which we would incorporate into the final contract to the winning competitor. We included a preliminary project schedule in the invitation to compete, which we asked them to accept on a best-effort basis.

      4.5 Selection Criteria

      We informed the competitors in advance of the criteria which would be used in making the final selection. They had to meet our technical criteria or, if not, demonstrate why their design was superior technically and commercially. Their design had to be aesthetically pleasing; this of course was a subjective issue. Their fee structure should be comparable to those prevailing in the market, but this was negotiable, if other conditions were met. They had to demonstrate that our project schedule would be met.

      4.6 Competition Outcome

      All eight short-listed firms submitted their proposals. We opened these in the presence of the two executive directors. A three-person evaluation team selected the two best proposals, and listed their merits and shortcomings. The evaluation team presented their results and recommendations to the directors, who made the final selection.

      The selected firm of architects had offered some innovative design ideas in their conceptual design. The roof structure design was even better than we expected, weighing about 6 lbs/sq ft. This would lower total costs by nearly 4%.

Figure 4.1 Folded Plate Design of Outer Walls

      The outer walls were designed as a folded plate (see Figure 4.1). The folded plate design strengthened the relatively slim stone wall (about 18” thick) considerably. It was strong enough to withstand the bending and buckling stresses caused by the wind and roof loads. Folded plate designs are normally used for concrete roofs, but using them for the walls was an interesting concept.

      The wall section on the inner part of the folded plate had large outward facing top-hinged window panels. The section of the wall forming the outer part of the folded plate walls had a large recess, which could be used for storage of tools, jigs, and fixtures (see Figure 4.1). A thinner outer wall section meant that fewer materials were required, so the walls would be cheaper.

      The main columns were spaced at 70 feet × 70 feet. With this spacing, we anticipated some problems with rainwater disposal because the down-take pipes could at best be spaced every 70 feet. This problem had to be solved during the detailed design, and was a situation about which we were aware. The provision for natural lighting was excellent, with large window areas in the outer walls and the north light roof structure design. Aesthetically, their design was pleasing.

      4.7 Results

      The factory СКАЧАТЬ