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

welfare and HSE grounds.

      5.Dust and Fume Pollution

      The dust pollution in the ceramics department and the fume problem in the plating department were potentially serious health issues. The existing extraction systems were clearly not effective, but the solutions were not obvious. At this stage, the project scope was to study the problem carefully, understand the causes, and identify solutions. We employed a specialist consultant to assist us, and the work took several months to complete. The problem was traced to the particle size of the ceramic dust. These were so small that much higher velocities were required at the extraction unit inlets. The project scope included the installation of cyclone separators and powerful extractor fans.

      At the plating department, we found that the fume extraction issue was more complex. The extraction hoods had to be redesigned and repositioned. Extraction velocities had to be increased, so new fans were required.

      The costs of these two projects were in the medium range, and the lead time of the equipment required meant that the project had to be scheduled in the third year. We justified it as an HSE project, but the results showed that there were other benefits as well.

      6.Security of Energy Supply to the Canteen

      The scale of the problems that the canteen faced on a daily basis was staggering. The local culture required that freshly cooked and piping hot food be served. The main staple was cooked rice, of which we needed on average, 10 oz. per employee. About 1500 meals were served in each batch.

      The rice was cooked in large electrically-heated cookers mounted on trunnions. Each batch had to be cooked in 20 minutes, and the vessel cleaned and ready for the next batch in 5–10 minutes. The water temperature had to be raised from the ambient 60–70°F to 212°F, and this could take 10–12 minutes. The canteen manager was visibly under stress. If there was any glitch, food could not be served—to at least 1500 and possibly up to 4500 waiting people!

      The electrical cooking system was excellent, but consumed significant amounts of energy. Because sunshine was available in plenty, we planned to install solar water heater panels on the concrete roof of the canteen. Each panel would be about 120 square feet in area. With four of them in series, even on a cloudy day we could get the water to 150–160°F in about 10 minutes. We decided to install two banks of four panels each along with an insulated hot water storage tank. This allowed us to supply hot water rapidly, and stored enough water for the second and third shifts as well. A structural design check of the roof confirmed that it was suitable for the additional roof loads.

      The project costs were in the medium range. Delivery of the solar panels would take 6–8 months, so we phased the project into the second year. The primary purpose was to get rapid supplies of fairly hot water to the cooking vessels, so that cycle time could be reduced. This would give recovery time to the canteen staff in the event of a power supply glitch. The bonus was that electrical energy savings made it economical as well. The project was justified as a welfare item.

      3.4 Results

      We completed all the selected projects within three years. When computing benefit-to-cost ratios, we measured or estimated the benefits over a 3-year period (thereafter, they would be influenced by other initiatives as well). The results are described below.

      1.Factory Ventilation (HSE)

      The air circulation fans were installed more or less on schedule. Some installations were late, caused by delivery delays from the vendor, but all the fans were in place within four months. Our departmental credibility went up a notch in the eyes of the workers.

      2.Electricity Supply

      There were budget overruns, as the transformers and circuit breakers cost nearly 30% over the estimate. This had to be offset by savings elsewhere. On the plus side, the value of production lost due to electricity supply problems went down by nearly 80%. The benefit-to-cost ratio was 5.5:1.

      The power factor capacitor banks and their control systems were very effective. The reduction in electricity bills was better than estimated, and the benefit-to-cost ratio was 6:1.

      3.Air Supply

      We installed pressure recorders at key points in the three factory buildings. The charts showed that after installing the air receivers, the pressure fluctuations were minimal and well within acceptable limits.

      Once the new cooling towers were connected, more than 95% of entrained water was trapped at the supply end. A small quantity was drained from the air receivers, but there was no water to be drained from the low point drains on the air mains any longer. The saw-tooth pipeline design described earlier was abandoned whenever new air lines were laid.

      Production loss due to air supply or quality problems all but disappeared once all the new facilities were installed. Computing the benefit-to-cost ratio proved difficult, as there were questions about the number of compressors to be included in the cost figure. The range was 11:1 to 16:1, depending on the cost figure selected.

      4.Water Supply

      Laying the new water mains proved very time consuming, as the municipality had complex and slow tendering processes for procuring and laying the pipe. There were city streets to be crossed; this required coordination with other city departments and utility companies. Eventually it was completed after about 30 months.

      We made better progress with the additional bore wells, about half of which turned out dry while the rest yielded varying amounts.

      Meanwhile, the demand was rising continuously. These two projects helped us to meet the demand, but there was no doubt that the problems would worsen in future. We did not compute a benefit-to-cost ratio as it was a survival and welfare issue.

      5.Dust and Fume Pollution

      The ceramics departments used to be in a permanent dust haze before we installed the new cyclones and larger extractor fans. The haze cleared visibly and quickly, so the workers were happy. But there was an attractive spin-off as well. Most of the ceramic dust recovered from the cyclones could be reused, allowing a small production volume increase and cost savings. What started off as a welfare/health project gave a benefit-to-cost ratio of 2.5:1.

      The new fume extraction hoods and fans in the plating department worked well from the beginning. The number of workers reporting sick dropped significantly, so we felt quite pleased with the results.

      6.Security of Energy Supply to the Canteen

      The solar water heater panel project produced dramatic results. The canteen people were relieved from the tension that prevailed earlier. They could go about their work calmly and with less anxiety. The savings in electrical energy paid for the project within eight months, which was a bonus.

      3.5 Lessons

      When management gurus talk about vision, mission, and objectives, we may find our eyes glazing over. However, this experience taught me that the gurus are quite right. A systematic approach allows us to objectively evaluate what needs to be done and why.

      As engineers, we do not always think in commercial terms; technical excellence is what most of us find appealing. Without an effort to do a cost-benefit analysis, I suspect these projects would have been shot down. When the benefit is 250% of cost (in some cases it was over 1000% of cost), it is easy to convince management. Funds suddenly become available to maintainers and engineers, instead of the much-favored Production and IT departments.

      We found that shop floor workers can be quite realistic in their expectations. When it comes to recognizing infrastructure weaknesses, their inputs are often quite useful. Visible feedback that they can see through our actions helps build trust and confidence. Shop-floor staff helped identify the main weaknesses during the two-week review period, not outside consultants. The items they highlighted proved valuable, as all of them had excellent economic or HSE benefits.

      That the boss is an important customer is not in question; not recognizing this can be career limiting! However, we should pay heed to the other customers as well, and include their ideas in our plans.

      Expectations should be vetted to ensure that they add value and are manageable within