Understanding productivity and the workflow process are important topics in construction education. It is easy to read a list of different items that can impact productivity and the work flow process in both positive and negative ways, but to have students experience these key items at work will have a lasting impact. To better understand the brief overview given at the beginning of the paper of some theories behind the exercise, read Appendix A. Appendix A, located at the end of the brief overview contains the directions and complete exercise for building the pipe model. This is a simple exercise that can be used in a lab setting to demonstrate to the students in construction education programs how to better plan for productivity improvement, and also, how to adjust management to solve productivity problems in construction.

Improving on the productivity goals set forth in construction estimates in construction means increasing profits and generally a project that will finish on time. On time and under budget seem to be the goals of most firms, project managers, and superintendents. Productivity is measured and stated as number or units of work completed divided by the number of labor hours needed to produce the work. In an equation: Productivity = Units of Work Produced/ Labor-hour Expended. The workflow process shows the progression of the work and the different paths the overall work can take to reach completion.

This exercise is to be used with a previous lecture on the factors that affect productivity and the workflow. The following list taken from the text titled Construction Jobsite Management written by Mincks and Johnston offers a starting place for the lecture on factors that affect labor productivity.

This exercise does not attempt to incorporate all of the factors listed, but the exercise does leave room for the individual instructor to change, customize, and incorporate the factors he or she wishes to emphasize.

Well-run projects seem to flow. Many corny analogies can be used when workflow is discussed in the classroom, but it is important that future managers and superintendents understand what workflow entails. In defining "work" in the term "workflow" the definition is generally referring to the key elements that make the "work" workable. This is a broad definition and would include the plans and specifications, the planning time, the ordering of materials, etc. Many of these items are not in the control of the people doing the direct work; but there are many items that are partially or completely in their control. These items could include tools, equipment, materials, and labor. The ability to plan the workflow and match labor against it is one of the key elements in the construction production process. It is important that students doing this exercise are allowed time to think about, plan, and implement the workflow on the pipe model.

Lead-time for the different activities of this exercise is not all the same. The exercise can be varied to put more or less pressure on any one of the workflow elements. For instance, shorter time for planning the building of the pipe model is allocated for the first group while the second group is observing and planning during the first construction of the pipe model. It should also be noted when discussing the workflow process which items need longer times and which items can be accomplished in a shorter time.

Another element of this exercise is work sampling. Work sampling has been used in the construction industry for many years. Work sampling can be defined as a method of measuring how labor, time and/or equipment are utilized on the project to complete specific work processes. This should result in the same information that cost control systems gather and report. In using work sampling in construction activities, individual workers are observed at a particular moment during a job related function on a regular basis. The observations fall into three or four categories. These categories are: Direct work (Primary time), Supportive work (Secondary time), and Delay (Recoverable lost time / rework). Some companies prefer to have an additional category called Standby. As part of the exercise and work sampling in general, the students must have a clear definition of each type of work. Having clear definitions will allow the results of the exercise to be discussed when the exercise is completed. Concerning the pipe model exercise, primary time is defined as the work that is affecting the task of completing the permanent structure. Measuring, holding the material for another as it is being installed, and installation of the permanent pieces are all considered primary work. Secondary time for the exercise is the supportive work of planning, supervision, the moving and handling of material, and instructing the primary work. The next category is recoverable lost work, rework, or delay types of work. This could be waiting for another worker to complete their task, standing and watching the process unfold, non-action or taking breaks, and taking apart and putting back together work that is wrong or will not accomplish the specification. Groups are allowed to use standby if they feel that the crew size set by the instructor is too large and a more appropriate crew size might work better. This exercise has observations happening at five-minute intervals with the same number of students watching the ones performing the construction.

By doing work sampling on the exercise, it gives the students and instructor one more point of discussion. The information gathered could also be applied against quantities extending the exercise even further. Direct work does not necessarily correlate with productivity, and with this exercise it may become apparent there is a real difference between students who have worked with their hands versus students who have not. Also, it should be understood that the pipe model can not be completed using the original drawings which are not exact, or with all precut pipe pieces. The plans do not show unions or a place for water to enter or exit the model. These two items have been left unchanged on the drawings and are used as points of illustrations for discussion. It is important that the student must understand and thoroughly plan his/her work along with having all material needed on hand to complete this activity. If not, this generally leads the students to rework along the process. If a team recognizes these issues early and requests unions, they are readily supplied the number requested up to a maximum of 6 unions. This also applies to the other issue of being able to charge the model with water. The students are supplied with tees, an inlet (hose connection) and outlet (hose bib value).

It has been observed during this exercise that the students are truly unaware of the complexities associated with the process of building the pipe model. The complexities can range from reviewing the plans, understanding the plans, allocating the right amount of time and communicating with their team mates concerning materials needed or work duties through the exercise. A quick review of the plans, that includes an isometric of the project to be built, illustrates that the model appears to be a very simple structure. It is a common belief that anyone can screw simple plumbing pipes together, but during the action of joining the pipe together problems associated with any construction project soon surface. The students must first determine the module that the model is designed around. Tees and elbows have different dimensions from their centerlines. Also during fabrication of the piece, small differences creep into the pieces. As students screw them together, different depths are achieved, just slightly changing the module again. Without preplanning, the teams generally try to achieve their much too aggressive "bid" time that was requested of each team. After thirty minutes or so the team tries to connect the loops in the model by back screwing (getting a little thread in each). It finally dawns on the students that additional parts are needed. The team may question or even ask for a union. (The unions also have a different center to edge dimension.) The team proceeds through the exercise still not planning ahead or really trying to understand what the module requirements entail. Other factors the students need to consider: what about holding water without leaking, and how does the water pass through the model? Again more rework and sometimes a breakdown of the team itself can occur. It is the instructor’s job to ensure the students stay on track and work through any disagreements or questions that may arise. The team is now nearing the ninety-minute mark and an end may be in sight. The model is tested, and because joints are not tight, unions not straight, the structure leaks and a fine spray of water is everywhere.

At this point, a discussion of planning for production ensues. Every student has ideas of how to better the three groups’ performances and every group is ready to attack the problem.

The learning objectives of the exercise are:

1. To give the student a first hand chance to observe the management factors that affect job productivity

2. To be able to articulate and apply recognized techniques that improve labor productivity.

Watching the exchange during the installation, the planning that goes on, and the discussion that follows will convince any instructor of the ability of this exercise to achieve the goals set forth by the exercise. There are many opportunities for the students to articulate and apply the instructor’s teachings from a previous lecture on productivity. The students walk away with a firm understanding of the complexity of building, the actions to achieving good productivity, and the requirements needed for better planning, leadership, and management. Most will be able to articulate the different factors that lead to a highly successful project or at least the factors that discourage success.

This exercise can be easily changed to fit each individual instructor’s emphasis. The students gain a broader understanding of the complexity of our industry and the importance of quality supervision. The pipe used is rigid steel, and holds up to demanding student use. Most instructors could ask their local plumbing subcontractor to fabricate the pipe pieces and nipples, or they can be purchased from any local hardware store. The drawing themselves also can be modified. These drawings were first used in a past ASC paper, Using Physical Pipe Models to Teach Construction Management Concepts by Ken Andersen and Norma Jean Andersen. Ken Andersen graciously gave me permission to use these plans but other set of plans could easily be self-developed.

Construction Jobsite Management, Mincks and Johnston, Delmar Publishers, 1998.

Construction Productivity Improvement, James J. Adrian, Elsevier Science Publishing Co., 1987

Improving Productivity, Jim Adrian, Construction Productivity Newsletter, Peoria, Illinois (309) 692-2370

Using Physical Pipe Models to Teach Construction Management Concepts, Kenneth W. Andersen and Norma Jean Andersen, Proceeding of the 29^th Annual Conference, Associated Schools of Construction

What Kind of Production is Construction? , Glenn Ballard and Greg Howell (1998) Proceedings Sixth Annual Conference of the International Group for Lean Construction,IGLC-6, Guaruja, Brazil, August 13-15.

Improving Work Flow Reliability , Glenn Ballard (1999) Proceedings Seventh Annual Conference of the International Group for Lean Construction, IGLC-7, Berkeley, CA, July 26-28, pp. 275-286.