Making the Most of Today’s Digital Drawings
Stumble into an estimator’s office prior to the computer age, and if you could push your way through the mountains of rolled-up plans, you might find your subject wearing sleeve garters and a visor, poring over plans reeking of ammonia with a triangular scale, further equipped with an electric pencil sharpener, columnar pads, a hand-held electric eraser, and a whirring electro-mechanical calculator. Not far from the office, you would find a storage area for paper plans, in most cases carefully arranged and cataloged to provide quick access to jobs in the bid process, jobs won, jobs postponed, and jobs lost.
When computers began to take over in construction, the estimating office landscape expanded to include personal computers that increased exponentially in power as the years passed. Estimating software gradually replaced calculators and writing implements as the estimator’s tool of choice. In the 1980s, electronic digitizers began to replace manual scaling as direct takeoff devices. In addition to obsolescing manual scales, digitizers used in conjunction with estimating software eliminated the step of manually keying scaled dimensions into the computer, always a source of errors and irritation. However, plans were still stored as before, needing more and more room as time went by. And you still located the estimator behind the same mountain of plans.
Computers or no computers, the basic process was the same: Develop takeoff quantities, then price them out, and compile them into an estimate. In both cases, it was up to the estimator to correctly associate the takeoff quantities with work items.
Today, the construction industry aims for a paperless office and a paperless work process. Most construction documents are now available in digital form as well as paper. As digital plans became more prevalent, specialized takeoff programs appeared that provided for on-screen measurements and counting. An estimator’s office today is likely to boast not one but two computer monitors: one devoted to digital plan display and measurement, and another for the estimating software that changes this raw data into a meaningful estimate. But whether they are running on two screens or one, the integration between digital takeoff and the actual estimate typically takes one of three forms.
Single-field integration is the technique typically used by spreadsheet and spreadsheet-based estimating software. It is characterized by a one-field-at-a-time work flow. For example, if the estimator is working in an assembly for walls, the estimating software may ask for the length of the wall. The estimator opens the takeoff software, finds the one measurement that is needed, and double-clicks to transfer the measurement to the estimating software. There is no organized display of takeoff information within the estimating software. There is also no attempt to intelligently link takeoff measurements with estimating logic.
Multiple-field integration allows takeoff information to be organized for presentation and use within the estimating software. Its distinguishing characteristic is a tabular display of takeoff data within the estimating software. The hierarchy usually corresponds to the individual measurements made by estimator, organized within the sheets from which they were taken. Each measurement carries forward whatever identification was used by the estimator during takeoff. While using the estimating software, the estimator can pop up the display of takeoff data and double-click data into any field at any time. The advantages over single-field integration include time savings, a better audit trail through storage of the takeoff measurements along with each estimate’s data, and ease of use.
Both of these types of integration leave the same task to the estimator as existed in the days of the Monroe calculator: To figure out how to price out the takeoff quantities. But the third method of integration finally frees the estimator from this time-consuming and tedious source of error.
Intelligent integration identifies the character of takeoff measurements and automatically links them to the appropriate building components in the estimating software. For example, when the estimator takes off a slab, intelligent integration uses artificial intelligence techniques such as pattern-matching to parse the identification of the slab, link it to the appropriate pricing technique within the estimating software, and automatically transfer the area and the perimeter of the slab. Units conversions, such as from inches to feet, can be easily handled. Within the estimating software, the remainder of the information needed to price the slab – concrete strength and placement method, finishing, fill, and so on – can be defined as defaults, and overridden as needed. Multiple sets of translations can be maintained to support multiple levels of desired estimate detail, different designers, or different types of work.
Intelligent integration of digital plan takeoff and estimating software is the first step toward bringing a meaningful estimating solution into BIM (building information modeling) integration. The basic techniques, which involve identifying design objects and associating them with estimating components, are the same. When the construction industry begins to exchange intelligent drawings, companies with the experience in today’s intelligent integration of estimating and “dumb” drawings will already be positioned to take the lead.
By Kevitt Adler, president, MC2.