07-Str-B2 · May 2017
Nivaar worked solution (AI-drafted; not reviewed by a licensed engineer)
Paper format: National Exams, May 2017 — 07-Str-B2 Management of Construction. Three hours, closed book, one approved Casio or Sharp calculator permitted. Six questions of equal value (20 marks each); any five constitute a complete paper and only the first five answered in the answer book are marked. All six are worked below so the paper can be used for revision whichever five a candidate chooses.
Reference texts: Hegazy, T., Computer-Based Construction Project Management (Prentice Hall) — activity-on-arrow networks, event-time calculations, time–cost trade-off and least-cost crashing, project cash flow and overdraft financing, and labour productivity; these chapters cover Questions 1, 3 and 5. Hendrickson, C. & Au, T., Project Management for Construction (2nd ed., Carnegie Mellon) — Chapter 10 (fundamental scheduling procedures), Chapter 11 (advanced scheduling techniques) and Chapter 12 (cost control, monitoring and accounting), including the S-curve and the financing of construction operations. Halpin, D.W. & Senior, B.A., Construction Management (4th ed., Wiley) — construction financing and the interest cost of a negative cash position, labour productivity and motivation, and construction safety management. Sullivan, W.G., Wicks, E.M. & Koelling, C.P., Engineering Economy (17th ed., Pearson) — Chapters 5 and 6, present-worth analysis and the repeatability (common multiple of lives) assumption for alternatives with unequal lives, used in Question 4. Peurifoy, R.L. & Schexnayder, C.J., Construction Planning, Equipment and Methods (9th ed., McGraw-Hill) — site layout and the physical determinants of crew output. AACE International, Recommended Practice 29R-03, Forensic Schedule Analysis, and the Society of Construction Law, Delay and Disruption Protocol (2nd ed., 2017) — the delay-analysis taxonomy required by Question 2. Canadian Construction Documents Committee, CCDC 2 — Stipulated Price Contract (2020), CCDC 40 — Rules for Mediation and Arbitration and CCDC 220/221/222 bond forms — the Canadian contractual machinery for notice, claims and dispute resolution. Transportation Association of Canada, Manual of Uniform Traffic Control Devices for Canada (MUTCDC), and the BC Ministry of Transportation and Infrastructure Traffic Management Manual for Work on Roadways, together with WorkSafeBC's Occupational Health and Safety Regulation (Part 18 Traffic Control, Part 4 lighting and workplace conditions, Part 8 personal protective clothing) — the Canadian rule set behind Question 6.
Question 1 (network). The node numbers, the activity letters and the i–j pairs printed in the data table agree completely with the drawn arrows: solid arrows run 1→2, 1→3, 1→4, 2→3, 2→6, 3→5, 3→6, 4→5 and 5→6, and one dashed arrow runs 2→5. The dashed arrow carries no letter in the table, so it is the network's dummy activity with zero duration and zero cost. Every arrowhead was checked individually at 8× magnification.
Question 5(b) (cash-flow chart). The values below are read from the printed chart. The smooth curve (cash out) reads 4.0, 11.5, 15.5, 45.0, 54.0, 71.5 and 71.5 thousand at the ends of months 1 to 7; the staircase (payment received) rises at the end of months 2 to 7 to 4.0, 12.5, 16.5, 47.5, 57.5 and 80.0 thousand. Both series are read to the nearest $500, which is the resolution the printed chart supports and is consistent with the word “estimate” in the question.
Question text not reproduced: the examination questions are © Engineers and Geoscientists BC. Open the official past paper (linked at the top of this page) to read the question, then follow the worked solution below.
Labour productivity is normally expressed as work-hours per unit of output, so a productivity loss is an increase in the hours needed to place the same quantity. On a typical building or heavy-civil project labour is the largest controllable cost and the only one that varies substantially with management quality, which is why productivity is the lever that most affects the outcome of a job.
Factors that impact productivity. They group naturally into five families. Design and information factors: buildability, the degree of repetition and standardisation, the completeness and timeliness of drawings, the rate of change orders, and the time taken to answer requests for information. Work that must stop while an answer is awaited is the most common single cause of lost hours. Management and planning factors: crew size and balance, the quality of short-interval planning, the availability of materials and tools at the workface, trade sequencing and the avoidance of stacking, supervision ratios, and the quality of the look-ahead schedule. Overtime belongs here too — sustained scheduled overtime beyond about four weeks reliably reduces hourly output through fatigue and absenteeism, so that fifty-hour weeks yield little more than forty-hour weeks at a much higher unit cost. Site and environmental factors: congestion, access and haul distance, working height, weather and temperature extremes, dust, noise, lighting on night work, and work in confined or occupied spaces. Labour factors: skill mix and journeyman-to-apprentice ratio, experience with the particular system, crew turnover, absenteeism and labour-relations climate. Project factors: schedule compression and acceleration, out-of-sequence work, learning-curve position, and the number of trades working in the same area at the same time. Quantified guidance for many of these — the productivity multipliers for overtime, temperature, congestion and stacking — is published in the Mechanical Contractors Association and Construction Industry Institute factor tables and is the standard basis for a disruption claim.
Arranging the site to improve productivity. Site layout is planning made physical, and its object is to reduce non-productive time: travel, waiting, re-handling and searching. The essential moves are these. Locate material laydown and storage as close to the point of use as the crane radius and haul routes allow, and lay it out so that materials can be delivered in installation sequence rather than sorted on arrival; double handling is pure waste. Plan the lifting envelope first — tower crane or mobile crane positions, radius, capacity at radius and hook time — because on a multi-storey job the crane is usually the constraining resource and everything else should be arranged around it. Provide a one-way circulation loop for delivery vehicles with a defined gate, a turning area and no reversing across pedestrian routes, which serves both productivity and safety. Segregate pedestrian and vehicle routes physically, and keep the walk from the site entrance and the lunchroom to the workface short: on a large site the daily unpaid walk can consume a measurable fraction of the shift. Place site offices, first-aid and sanitary facilities where they are convenient enough to be used without a long detour. Provide power, water, compressed air and temporary lighting distribution at the workface rather than at the perimeter, and enough temporary heat and hoarding to keep winter work productive. Provide fabrication and pre-assembly areas at ground level so that as much work as possible is done in a shop-like environment instead of at height. Keep the site clean and orderly — a scheduled and funded housekeeping crew, waste bins at the workface and clear stair and corridor routes; the return on this is out of all proportion to its cost. Finally, plan the layout dynamically: the arrangement that suits excavation and substructure is the wrong one for finishing trades, so the layout should be re-drawn for each major phase.
Morale and motivation. Motivation research in construction, from the Hertzberg two-factor framework onward, points consistently to the same conclusion: pay and physical conditions are hygiene factors that cause dissatisfaction when they are inadequate but do not by themselves produce sustained effort, while recognition, achievement, responsibility and the sense that the work is well organised are what actually drive output. The practical measures follow from that. Remove the frustrations first: nothing demotivates a skilled tradesperson faster than arriving at a workface without materials, tools, information or access, so reliable short-interval planning is itself the single most powerful motivator. Set clear, achievable goals at crew level with visible feedback — a weekly target for metres of pipe or square metres of formwork, posted and reviewed — because goal-setting with feedback is the best-evidenced productivity intervention there is. Recognise good performance publicly and promptly, in toolbox talks and in front of peers, and make it clear that the recognition comes from the person's own supervisor. Involve crews in planning the work they will do; the last-planner approach of having foremen make their own weekly commitments and measure percent-plan-complete both improves the plan and creates ownership of it. Invest in supervision: the front-line foreman is the largest single influence on crew morale, and training foremen in planning and in people management repays itself quickly. Provide training, apprenticeship and a visible path of advancement, which improves both skill and retention. Treat safety as the demonstration that the company values its workers — sites with strong safety cultures reliably show higher productivity, because the same discipline that produces good safety produces good planning. Where incentives are used, apply them at crew rather than individual level, tie them to quality and safety as well as quantity so they cannot be earned by cutting corners, and keep the measurement simple enough that workers can see how their effort maps onto the reward.
