MATERIAL & EQUIPMENT MANAGEMENT

Machines and Materials are a vital resource to the accomplishment of any construction project. They enable effective working at any construction site for works that cannot be practically be executed only by manpower.

SCOPE OF WORK

Civil works for development of 100m wide landing strip, International Airport.• Carrying out earthwork in excavation in any material met on site, up to the

required level by mechanical means i.e. excavators.• Backfilling in burrow to achieve required level 80,000 Cum earth, disposal

of overburden waste of 20,000 Cum to a lead of 3Kms and spreading the same.

• Proving and laying sand over leveled surface, 3,000 Cum from 20kms, including spreading & leveling.

• Procure, store and applying Bitumen over sand bed, from Bangaigon, Assam, of 150,000 Liters.

DESCRIPTION OF EQUIPMENTS CONSIDERED FOR THE WORK

Earthmovers: These machines used for earth cutting, moving or transporting large volume of earth. A brief description of the equipments used for excavation is reported as follows.Here we have considered the following machinery for the task to be executed:

1 Nos. crawler mounted Hydraulic excavator, TATAEX350 LCH - V Super BUCKET CAPACITY: 1.30 - 1.90 m3. For excavation & loading to dumptruck.

1 Nos. Motor Grader-Articulated TATA Hitachi Motor grader TG-14 for dozing, surface dressing, leveling spreading of sand.

5 Nos. Truck Tipplers TATA HYVA 2516 for Hauling of earth excess earth mass 20000 Cum 3kms away from the site & dumping of earth where filling is required 80000 Cum, also to bring sand from 20Kms of Vol.3000 Cum.

• Hydraulic Excavators-Crawlers : These are Single-bucket excavator’s names as classified according to running gear as crawler-mounted, wheeled, walking, rail, floating, and combination rubber-tyres. These are used for excavation, moving earth & loading. The benefit of crawler is that it can easily move in any type of soil. Easily load earth to the hauling machine.

• Motor Grader- Articulated : These commonly referred to as a road grader, a blade, a maintainer, or a motor grader, it is a construction machine with a long blade used to create a flat earth surface. These machines have blades which can be positioned at front as well as centre depending on site and nature of work. These are generally used for area grading and where low cutting and filling is to be done.

• Truck Tipper : A tipper, is a dump truck used to haul earth mass, rock, sand gravel, asphalt, trash and anything else that needs hauling and dumping. It is widely used for construction purpose, mining purpose, domestic goods transportation purpose and many other. It is rubber mounted, uses hydraulic hoist to dump the materials mechanically. Generally it is rear duping system. There are also dumpers with side unloading systems.

• Asphalt Paver : The asphalt pavers are capable of laying large quantities of hot asphalt and leveling it to the required condition.

• Asphalt Sprayer : The asphalt sprayer melts the bitumen and sprays it at the required area. It has a burner in it which can maintain the temperature of the bitumen at over 350 degree C.

CALCULATION OF PER DAY WORK

The total work to be planned for execution per day can be calculated as below. Total No. of days = 100.Working Hours. = 10 hours/ Day.

IDENTIFICATION OF ACTIVITIES:

The major activities can be listed as below:1. Earthwork in excavation 100000 Cum.2. Hauling of overburden 20000 Cum. Up to lead of 3Kms.3. Bringing Sand 3000 Cum. From 20Kms.4. Leveling of surface & spreading of sand.5. Procurement of 150000 liters of Bitumen.6. Planning for application of bitumen and procurement keeping in view that

total available storage at a time is 1/3 of total requirement

PLANNING OF ACTIVITY:

Activity 10 20 30 40 50 60 70 80 90 100

Earthwok in

excavation

Leveling and dressing

Sand filling

Order for Bitumen

Delivery of Bitumen

Replenishing of

Bitumen

Removal of over

burden

Spreading of Soil

Factors That Affect Selection of Equipment

1. Earth Moving Equipment:The selection of earthmoving equipment mainly dependents on:-

• Quantity of earth to be moved.• Completion Time.• The decision to choose between crawler-mounted earthmoving

equipment and a wheel-mounted one depends to a large extent on the prevailing job conditions.

• Payload & Cycle time• The number of associated equipment required to support the main

equipment i.e. Loaders& Dumpers.• Cost of Owing & Operation.• Average age In-Service & Equipment useful age.

2.Earth Hauling Equipment:

The selection of earth hauling depends mainly dependents on:-• Quantum of Work• Space for maneuvering & terrain.• Cost of Owing & Operation.• Fleet equipment characteristics• Expected project duration.• Nature of Work.• Distance of Hauling.

• Average age In-Service & Equipment useful age.

Mass Diagram

CUMMULATIVE METRIC VOLUME

END AREAS VOLUME (CUM) ALGEBRIC

STATION (SQ) SUMS

CUT FILL CUT FILLVOLUMES,

CUMULATIVE

0 186 0 0.000 0.000 0.000

1 65 0 17836.594 0.000 17836.594

2 44 0 7748.370 0.000 25584.964

3 22 0 4679.708 0.000 30264.672

3.5 0 0 767.165 0.000 31031.837

4 0 22 0.000 -529.276 30502.562

5 0 44 0.000 -3228.581 27273.981

6 0 65 0.000 -5345.683 21928.298

7

0 166 0.000 -12305.657 9622.641

8 0 119 0.000 -14899.107 -5276.466

9 55 46 2493.287 -8071.452 -10854.631

9.08 0 0 191.791 -185.246 -10848.086

10 0 22 0.000 -979.160 -11827.245

10.5 0 0 0.000 -529.276 -12356.521

11 22 0 767.165 0.000 -11589.356

12 44 0 4679.708 0.000 -6909.647

13 87 0 9282.700 0.000 2373.053

14 218 43 21595.704 -2117.102 21851.655

15 64 22 19984.657 -3175.653 38660.658

15.07 0 0 345.224 -238.174 38767.709

16 32 0 2109.705 0.000 40877.413

16.5 0 0 1150.748 0.000 42028.161

17 0 32 0.000 -793.913 41234.248

18 0 61 0.000 -4551.770 36682.478

19 0 157 0.000 -10717.830 25964.648

20 90 95 6367.472 -12332.120 20000.000

Cost Analysis:

Cost of equipment operation per hour and cost of each item of work.Calculation of Per day work.Total Quantity of Earth= 1,00,000 CumNo. of Days= 60 Days.Volume of Earth to be moved per day per hour= 100000/60/10Hence Hourly production required=166.66 Cum per Hour.

1. Determine of the material type and bucket fill factor.Average Soil = 85 to 90%

2. Estimate the Cycle Time Referring to the supplier's equipment cycle time estimating chart Average = 0.43 to 0.52 minute

3. Calculation of Effective Cycles per Hour Divide the 60 minute hour by cycle time and adjust for availability and efficiencies.

Cycle Time 0.48 minuteCycles/60 minute hour 60 / 0.48 = 125Operator Skill/Efficiency 0.9 (90%)

Machine Availability

0.95(95%)

Gen Operational 0.83(50 min/hr)Efficiency

Effective Cycles per 125 x .9 x .95 x .83 = 89Hour

4. Calculate the Required Bucket Capacity

Divide hourly production requirement by effective cycles per hour, adjust for material density and fill factor.

Hourly production 166 Cum / hourRequired

Effective cycles / hour 89= Required Payload 166 / 89 = 1.87 Cum

Material Density / Loose 1.6 Ton / m3= Bucket Payload Volume 1.87 / 1.6 = 1.17 m3

Fill Factor 0.85 (85%)= Nominal Bucket Size 1.17 / .85 = 1.38 m3

Hence Considering TATA EX350 LCH - V Super BUCKET CAPACITY: 1.30 - 1.90 m3The cost breakdown structure for owning and operating cost of all the fleet equipment has to be paid larger importance as this is the vital statistic which can make the project into Profit and if not considered may lead to financial loss to

the project.Equipment operation cost accounts for the three main categories of cost.1. Owing cost2. Operation cost.It is the cumulative sum of expenses an owner experiences by working a machine on the project. It is sum of expenses like fuel, lube oil expenses, grease, repair & maintenance of machinery.

Fuel expenses are determined by measurement of the job. This can be determined by records of consumption of fuel in liters per hour knowing job conditions, viz. if the soil is loose machine can do more volume of work in comparisons to the work where the strata of soil is harder. Average hourly consumption of fuel can be calculated directly knowing the soil properties of the project from previous recorded statistics.Similarly, the cost of lube oil and replacement of tier required can be worked out by knowing the machine characteristics and abrasion, life tier

3. Wages of Equipment Operators.Operator wages may be included in Operation cost, but due to the variance of projects , it is generally practiced to keep the Wages of Equipment Operator is a separate category. The justification behind this is, since every project may have different scheme, sometimes the operator may be paid on hourly basis sometimes may be in Percentage and sometimes in the volume or work done.

The cost should include all benefits paid by the company as per its policy.

Cost of Owing can be determined by knowing1.Estimated Ownership Period in years.2.Estimated Usage (Hours/year)3. Ownership usage (Total Hours)

Operating Costs:

1. Fuel Cost & Consumption rate (Units/hours)2. Lube Oils, Filters, Grease.

3. Tyres4. Repair reserve (Extended use & Basic repair)

Fuel cost can be calculated on the theoretical basis.

The resulting theoretical values must be adjusted by time and load factor that account for working conditions. Time factor-Actual working time of machine. Load factor-Percentage of rated horsepower.

NAME OF EQUIPMENTS:

1. FOR EQUIPMENT USED DEPARTMENTALLY(I) Ownership charges:

(a) Total investment at site of work (this includes A/T cost,

Sales tax, excise, custom and other duties, transport expenses consisting of freight (by ocean & rail) insurance loading/unloading charges and erection and commissioning on receipt) …………………………………………….……………Rs. 50,00,000.00

(b) Deduct salvage value@15 percent of A…………………………………………………………. Rs. 7,50,000.00

(c)Total investment to be depreciated = A-B……………….……………………………………….….Rs. 42,50,000.00

(d)Economic life of the machine in hours as per appendix 7.II(as per Ministry norms, it is 9000 Hrs.) Hrs.

(e) Depreciation per hour [ C/D ]…………………………………………….……………...Rs.472.22

(f) Storage charges per hour (1 percent of “c” spread over the economic life) = 0.01x (C)/(D)………….Rs 4.72

Total ownership charges = (E)+ (F) Rs.476.94…(I)

II Operational Charges

Repair charges per hour including maintenance and replacement of tyres (150 percent of “C” spread over

Economic life =1.5xC/D……………………………………....Rs.708.33…(II)

III Overhead Charges:

@ 5 percent of ownership and operational charges=5(I+II)/100Overhead charges per hour……………………………………Rs. 59.23… (III)

IV Running Charges:Operating staff/labour & wages: No. Wages/monthDesignation(i)Operatior @ 584.21 per day(ii)Helper @ 428.00 per day(iii) Cleaners @ 89.36 per day(iv) Misc. Expenses (Welder) @5%(v)TA. Etc.@ 15%(H) Wages Per hour

Total Operating Cost per Hour………………………………….Rs.165.23 … (J)

(J) Servicing Chages: Fuel Lubricants, etc.

Consumption/hr. Rate/Litre Cost/hr.

1. Fuel @7liters per Hour....cost per hour = 14Liters X Rs.41.29 per Liter= Rs.578.06

2. Lubricants, Grease, Hyd.Oil, gear oil, Cotton Waste, etc. @ Rs.52.73per Hour. Total Service Charge per Hour……………………….Rs.630.79…(K)K Cost of Lub. Oil, Fuel etc. hr.

Total Running charges per hour (J + K)

…………………………………………………………….Rs.796.0…… (IV)

V. Overhead charges @ 5 percent of the total charges

per hour = 5 x L/100 = Rs.39.80……………………………………(V)

Summing up:

Ownership charges = I =Rs.476.94…(I)

Operational Charges = II = Rs.708.33…(II)

Overhead of I and II = III = Rs. 59.23…(III)

Running charges (as in 5) = IV = Rs. 796.02…(IV)

Overhead charges on IV = V = Rs.39.80 (V)

Cost of Equipment Operation per hour= (I+II+III+IV+V) = Rs.2080.32.

Approx. Rs.2081.00 per hour

Calculation for Dumper:

Earth haulage or transportation. It is to determine not only the most suitable method of hauling material, but also to determine most effective and economical means or equipment to use for operation of shifting earth. The rear dumpers & tractors with hydraulic dump are mostly used in transportation of earth. These units have the body that is mounted on a frame of a truck. Dumping is carried out by raising the box with a hydraulic system. There are common types of trucks that are capable of handling all types of earth material. Physical site conditions and economic considerations may operate as controlling factors in selecting the equipment based on its size. optimum assignment of dumpers to the excavators and minimize the idle time of the excavator. The excavation-loading seeks to combine two basic equipment in view of achieving efficiency and productivity. If the excavation rate of a machine remains constant, and if the loads and cycle times of the dumpers to remain constant, it would be fairly simple to

determine the most economical number of dumpers to employ on a specified project. However, it is well known that dumper cycle times do not remain constant even though the haul road profiles and the number of dumpers operating remain constant. There may be times when dumpers are waiting in a queue to be loaded; then later, for no apparent reason, the excavator may have to wait for a dumper. This results in a loss in production. If more dumpers are employed, there will be an excess of dumper capacity. But often there is not enough benefit to compensate for an increased cost of extra dumper(s). This loss of productivity occurs because of a mismatch which causes bunching of the hauling units. The improvement can be done by minimizing both the idle time of equipment and handling cost per cubic meter of earth. The number of dumpers required for the earthwork is determined by comparing various fleet production capabilities and costs. Requirement of selecting the lowest cost fleet with adequate production capability. In other words, dumper fleet requirements are affected by many factors; site conditions, output requirements, loading equipment, equipment performance and cycle time, operating methods and practices, matching of loading equipment and dumpers, and equipment availability and utilization. The suitability of a loading equipment to a hauling dumper and the selection process of a dumper fleet consist of 1. The maximum capacity of a dumper depends upon the site conditions and

quantum of work. This differs from project to project, but generally, it is about eight times the bucket capacity.

2. The minimum capacity of the dumper should be approximately four times larger than the excavator bucket capacity.

Match Factor= number of haulers x loader cycle time/ number of loaders x hauler cycle time. The perfect match point from the theoretical standpoint is 100 percent, the dumper-shovel fleet efficiency, which occurs when the match factor equals to1.

CYCLE : VOLUME CALCULATION

Measured parameters Calculated parameters

Excavator Dumper

NumberBucket

Avg.Avg. Cycle Match Totalloading of

cycletime

Timedumper

factor Efficiency (%)

time(sec) (min)(min)

1 0.23 22.63

2 0.45 45.27

3 0.68 67.90

28.8 2.75 12.15 4 0.91 90.53

4.5 1.02 101.85

5 1.13 113.17

6 1.36 135.80

7 1.58 158.44

Truck considered of 9MT capacity & 5.5 Cum in loading volume.Cost of Dumper per day @ Rs 2100.00 X 5nos X 60 days= Rs.6,30,000.00(Additional One Truck is required for transportation of sand & Removal of Overburden)

Total Cost of Work:

Excavation:Total Earthwork to be done= 100000.00 CumNo.of days = 60 Days.60 days X 10 Hours X 2081= Rs. 12,48,600.00

Total cost of Excavation & Hauling= Rs.17,52,600.00Motor Grader for leveling the site @ Rs.2,450.00 per Hour

Cost of Sand.

Sand Quarry Lead 20Kms, Cost at quarry Rs. 79 .00 Carriage charge @ Rs.6.08 per Kms= 121.60

Sacking charge@ Rs.3.05 per Cum. (Including labour, Loading & Unloading Charges) Cost of sand spreading & leveling at Site@ 55.00 per Cum

Cost of sand = Rs.79+ Rs.121.60+Rs.3.05+ Rs.55.00 =Rs.258.65 Total Cost of Sand = 3000 Cum. X Rs.258.65 = Rs.7,75,950.00

Cost of Bitumen.

Cost of Bitumen at Bongaion Plant.Rs. 38170.00

Cost of transportation= Rs.568.10 per Truck. Additional Rs.8.34per Kms Consider site 1000kms from Plant

Hence cost of transportation= Rs568.10+Rs.8340.00= Rs.8964.91 Consider Stacking, loading unloading cost @ 2%= Rs.167.93 Per MT

Cost of Bitumen= Rs.38,170.00 + Rs. 163.93 + Rs.896.49= Rs.39,230.42 Per MT Cost of 1,50,000.00 Lit=2403 Kg per cum, = 360.45 MTTotal Cost of Bitumen = 360.45MT X Rs.39230.42

=Rs.1,41,40,604.89 say Rs. 1,41,40,605.00

TOTAL COST OF WORK= Rs. 17,52,600.00

Rs.7,75,950.00

Rs. 1,41,40,605.00

Rs. 1,66,69,155.00

MATERIAL MANAGEMENT

Material management plays a vital role in achieving the target completion date. Material management is planning & controlling of the functions supporting the complete cycle of materials, and the associated flow of information. These can be achieved by Identification of Critical & Most Critical materials required, Standardizing by formulation & Implementation of Guidelines to achieve harmony within the activities. Determining the period, start & end of the project preparing schedules, procure materials as per schedule, storage, inventory control, distribution as per requirement & dispose.It confirms that the material reaches the site before the time of its requirement at the same time it also ensures that the fund is not blocked by purchase of material too before they are required at site.

EOQ – economic order calculation.

As we are procuring Bitumen from Indian Oil Corp. Bangaigaon, Assam, how many would we order “at a time?” If we order a large quantity each time we order, we’ll end up holding some bitumen in inventory for a longer time & than if we had ordered a smaller quantity. With a higher quantity, inventory cost goes high.If we order a small quantity, we’ll end up paying any setup and/or fixed costs more frequently. For example, the driver of the truck delivering the bitumen is paid the same, whether the truck is loaded with 10MT bitumen or 2MT bitumen. If we order only 2MT

bitumen at a time, we’ll have to pay transportation 5 times more … than if we had ordered 200MTbitumen at a time. With a smaller quantity, setup and/or fixed cost goes high.Since a higher quantity is not best … and a lower quantity is not best … there must be some “middle” quantity where the total cost (inventory cost PLUS setup and/or fixed cost) is least expensive. Below is a chart that illustrates the relationship:

Total Cost

Inventory CostC

o

sSetup Cost

Quantity

The point of lowest total cost can be seen to be at the “very bottom” of the Total Cost curve. The quantity associated with that point just also happens to be the same quantity at which the two other lines intersect. To calculate the quantity at that point, use the formula below:

_______________________________________EOQ = √ [ 2 (Demand) (Setup Cost) ] / (Inventory Cost)

That formula results from using calculus to take the derivative of the Total Cost function at zero. When this formula is used to calculate how many to MAKE at a time (instead ofHow many to BUY at a time), it is sometimes called the Economic Manufacturing Quantity ……. or EMQ.Calculation of EOQ.

R = Forecasted monthly usage………………… 1,50,000.00 Lit=2403 Kg per cum, = 360.45 MT

C = Cost per order event (not per unit)…… ……………….Rs. 3,53,073.60 (9MT in One Truck)

P = Purchase cost per unit……………………………………………Rs. 38170.00 (Cost at plant)

H= Holding cost factor….......................................................................Rs. 41,987.00 (F=1.1 X P)

Q*= 77.86 MT ~ 32401 Liters Approx.

Re-order level (ROL)

Receiving and issuing of inventories are the common and recurring phenomena in a manufacturing organization. When the inventories fall below a particular level, they are replenished by the fresh purchases. The prescription of re-order level (ROL) is an important technique of inventory control. It fundamentally deals with ‘when to order’ to replenish the inventories. Re-order level is predetermined point, and when the existing stock of inventories reaches this point of falls below it, the purchase action is initiated to replenish them. The ROL is mentioned in the bin-card of each inventory item. What should be the quantity of replenishment order is also a matter of policy. Generally, size of

the order is determined on the basis of the economic ordering quantity (EOQ) which is also an important technique of inventory control.

Detailed treatment is given to this technique separately.

The re-order level is decided for each important item of inventory on the basis of following considerations:

1)Lead time

2)Average periodic consumption (daily consumption)

3)Safety stock

Re-order level is decided as under:ROL= (Lead time x average daily consumption) + safety stock Here, Lead Time = 4 days.Average periodic consumption per day = 5000 Liters Safety Stock 5000 Liters.ROL= (4x5000)+5000 = 25000 Liters

Ordering schedule, for Bitumen.

As per the given criterion, the site has a storage capacity of only 50,000 liters of bitumen at a time. Hence the schedule for procurement of bitumen can be decided as follows to ensure timely consumption of bitumen and also timely procurement. It is given that the lead time for bitument from a refinery in Bongaigaon in Assam is 45 days. Hence:

Order for bitumen to be placed in lots of 50,000 liters each as follows:

Lot number Day of indent from Day of receipt Days for consumption 1st day1 15th day 60th day 10 days2 25th day 70th day 10 days3 35th day 80th day 10 days

BIBLIOGRAPHY:

A Statistical Analysis Of Construction Equipment Repair Costs Using Field Data & The Cumulative Cost Model by Zane W. Mitchell, Jr.

Managing Construction equipment S. W. Nunnally

Construction Planning Equipment & Methods- Peurifoy/Schexnayder/ Shapira

Optimizing Economic Order Quantity (EOQ)- By Dave Piasecki

GOVERNMENT OF INDIA CENTRAL PUBLIC WORKS DEPARTMENT 2012 DELHI SCHEDULE OF RATE