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Gửi các bạn một bài viết của một chuyên viên dự toán đăng trên tạp chí Estimating Today:
Things I Have Learned in 37 Years of Estimating
Erle Howard
I was asked during an estimating class for some rules of thumb for checking estimates. I guess I should be flattered that someone thinks I know something about estimating because of my age and experience. I must say that I learn something new about my profession every day from almost every student I train.
The following thoughts are a result of that request. The advent of computerized estimating has been a mixed blessing for most of us. While I do electrical estimating only, I think this list applies to all estimating disciplines
Things we gain from using estimating software:
• Speed
• Accuracy
• Time to check our estimates
• The means to check our estimates with various reports and graphs in our estimating software
• Historical data to check future estimates
• Consistency
Things we may lose by using estimating software:
• We may lose knowledge; before computers I could tell someone how many hours it took to install 4” EMT; now I have to look it up on the computer!
• We may lose control of our bidding volume. Too often, management will bring in more drawings for you to bid because we are faster at what we do when we use a computer estimating software package.
Things to think about:
• Never bid a job more than twice the size of the largest job that you have completed.
• Beware of jobs far from your home base.
• Beware of unfamiliar general contractors.
• Always know and understand your costs.
• Know what your overhead costs are. Overhead is a cost to run your business, and you will spend it; most contractors discount their overhead costs and that may cause a loss on the job.
• You can’t sell milk for $2.00 when it costs $3.00.
• You cannot make up a loss by increasing volume.
• Know your competitors. If you know what your competitors are likely to do, you can adjust your bid to gain an edge. (Did they get the last big bid? If so, they may go high on this bid. Or, are they hungry for work?)
• Always bid the job and not the market.
• Beware of people asking you to cut your price.You may already be the low bidder.
• Do not base your bid on future change orders. Most of us lose money on change orders.
• Do not bid a job based on the hope of future tenant work. Many times the tenant work goes out for bid.
• The job you got and thought you had a good margin on will probably be a loser, but the job
you got and were nervous about will probably make money because you will micromanage the
project.
• Do not sign a bad contract. I see too many contractors signing bad contracts! How can you
allow a contract to tell you that all change orders can include only 10% overhead when you are
spending 20%?
• Send a detailed scope letter to your general contractors at least a day before the bid. Tell them what you include and what you exclude from your bid.
• You know how much trouble you have comparing supplier quotes at the last minute; multiply that by the number of sub-contractors the general has to review, and you know what a time-consuming project that is for the GC.
• A good scope letter helps the GC select you as the bid winner.
• A bad scope letter will help the GC eliminate your bid.
• As estimators, we need to spend a lot of time checking our estimates for errors. Most estimates are a series of errors. Find the errors!! The old expression “garbage in, garbage out” still applies.
• The computer will add any number of items or assemblies you ask for so you had better check what you have. Do an order-of-magnitude check. Check every large and small extension. Why are they high or low? Is there a mistake in the quantity or price?
• Engineers are low bidders or they would not get the project, the same as contractors. Find the time to do whatever reengineering necessary to give you an edge on your bottom line. Combine home runs; relocate anything that you can to save money.
• If you are looking through Dodge Reports or CMD to find jobs to bid, you are probably wasting your time, as there are too many bidders chasing jobs. Find your place in the market (design build, government work, anything other bidders will shy away from).
Through the years, I have learned from others these following checks for accuracy in an estimate:
Rules of Thumb
• If you cannot control your estimating volume, you cannot control the quality of your estimates.
• Divide the total feet of branch wire by the total feet of conduit to find the average number of wires per conduit foot. This should equal approx. 3.68 wires per foot.
• Divide the total feet of conduit by the total number devices to check the footage per device. Commercially this should be about 20’ for receptacles, about 10’ per lighting fixture, 50’ per fire alarm device. This may vary but should be a good rule of thumb. If you find differences from the averages, you need to check your estimate to see why.
• This information is useful for budget estimating when you do not have the time to do a full estimate
A typical commercial estimate will have the following labor and material ratios:
Item : Labor/ Material
Branch Conduit: 53% / 38%
Branch Wire :11%/15%
Feeder Conduit : 2% /4%
Feeder Wire : 5% /32%
Devices :5% /9%
Gear :8% /0%
Fixtures :10%/ 1%
Wire term :3%/ 1%
Total : 100% /100%
How can estimating software help?
Things I Have Learned in 37 Years of Estimating
Erle Howard
I was asked during an estimating class for some rules of thumb for checking estimates. I guess I should be flattered that someone thinks I know something about estimating because of my age and experience. I must say that I learn something new about my profession every day from almost every student I train.
The following thoughts are a result of that request. The advent of computerized estimating has been a mixed blessing for most of us. While I do electrical estimating only, I think this list applies to all estimating disciplines
Things we gain from using estimating software:
• Speed
• Accuracy
• Time to check our estimates
• The means to check our estimates with various reports and graphs in our estimating software
• Historical data to check future estimates
• Consistency
Things we may lose by using estimating software:
• We may lose knowledge; before computers I could tell someone how many hours it took to install 4” EMT; now I have to look it up on the computer!
• We may lose control of our bidding volume. Too often, management will bring in more drawings for you to bid because we are faster at what we do when we use a computer estimating software package.
Things to think about:
• Never bid a job more than twice the size of the largest job that you have completed.
• Beware of jobs far from your home base.
• Beware of unfamiliar general contractors.
• Always know and understand your costs.
• Know what your overhead costs are. Overhead is a cost to run your business, and you will spend it; most contractors discount their overhead costs and that may cause a loss on the job.
• You can’t sell milk for $2.00 when it costs $3.00.
• You cannot make up a loss by increasing volume.
• Know your competitors. If you know what your competitors are likely to do, you can adjust your bid to gain an edge. (Did they get the last big bid? If so, they may go high on this bid. Or, are they hungry for work?)
• Always bid the job and not the market.
• Beware of people asking you to cut your price.You may already be the low bidder.
• Do not base your bid on future change orders. Most of us lose money on change orders.
• Do not bid a job based on the hope of future tenant work. Many times the tenant work goes out for bid.
• The job you got and thought you had a good margin on will probably be a loser, but the job
you got and were nervous about will probably make money because you will micromanage the
project.
• Do not sign a bad contract. I see too many contractors signing bad contracts! How can you
allow a contract to tell you that all change orders can include only 10% overhead when you are
spending 20%?
• Send a detailed scope letter to your general contractors at least a day before the bid. Tell them what you include and what you exclude from your bid.
• You know how much trouble you have comparing supplier quotes at the last minute; multiply that by the number of sub-contractors the general has to review, and you know what a time-consuming project that is for the GC.
• A good scope letter helps the GC select you as the bid winner.
• A bad scope letter will help the GC eliminate your bid.
• As estimators, we need to spend a lot of time checking our estimates for errors. Most estimates are a series of errors. Find the errors!! The old expression “garbage in, garbage out” still applies.
• The computer will add any number of items or assemblies you ask for so you had better check what you have. Do an order-of-magnitude check. Check every large and small extension. Why are they high or low? Is there a mistake in the quantity or price?
• Engineers are low bidders or they would not get the project, the same as contractors. Find the time to do whatever reengineering necessary to give you an edge on your bottom line. Combine home runs; relocate anything that you can to save money.
• If you are looking through Dodge Reports or CMD to find jobs to bid, you are probably wasting your time, as there are too many bidders chasing jobs. Find your place in the market (design build, government work, anything other bidders will shy away from).
Through the years, I have learned from others these following checks for accuracy in an estimate:
Rules of Thumb
• If you cannot control your estimating volume, you cannot control the quality of your estimates.
• Divide the total feet of branch wire by the total feet of conduit to find the average number of wires per conduit foot. This should equal approx. 3.68 wires per foot.
• Divide the total feet of conduit by the total number devices to check the footage per device. Commercially this should be about 20’ for receptacles, about 10’ per lighting fixture, 50’ per fire alarm device. This may vary but should be a good rule of thumb. If you find differences from the averages, you need to check your estimate to see why.
• This information is useful for budget estimating when you do not have the time to do a full estimate
A typical commercial estimate will have the following labor and material ratios:
Item : Labor/ Material
Branch Conduit: 53% / 38%
Branch Wire :11%/15%
Feeder Conduit : 2% /4%
Feeder Wire : 5% /32%
Devices :5% /9%
Gear :8% /0%
Fixtures :10%/ 1%
Wire term :3%/ 1%
Total : 100% /100%
How can estimating software help?
- • A good program will have utilities built in to give you data needed to check your estimate. Most programs can break out the Cost Codes (branch rough-in, branch wire, lighting fixtures, feeders, etc.) If you look at it, this is also a schedule of values for your bid. It used to take days on a large project to do the break-outs for billing. Most programs can keep track of historical data such as square foot cost. The McCormick Systems Program can provide graphs of the project bid summary, including all job costs and labor hours broken down by cost code.
- Spend time keeping and studying historical data on every bid.
- Plug in the square foot of project in the Bid
- Summary to see the square foot price for your project.
- Know your square foot price and compare that to each similar bid. Why is it high or low? Find out why there is a difference; it could be a mistake you need to correct.
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