Construction Operations

Decision levels · project lifecycle · sixteen models

Construction operations research asks how a project owner, contractor, or subcontractor can allocate capital, crews, equipment, materials, and time to deliver buildings and infrastructure on budget, on schedule, and to specification — across horizons that stretch from a single day's dirt haul to a decade-long portfolio of projects. CPM and PERT were invented in this domain in 1959 (Kelley & Walker for DuPont, Malcolm et al. for the Polaris missile programme); today the Resource-Constrained Project Scheduling Problem (RCPSP) and its >150 catalogued variants remain an active research frontier. This section presents sixteen canonical OR problems, each as a live interactive solver grounded in a real construction decision, organized along the decision-level × problem-family taxonomy inspired by Hartmann & Briskorn (2010, 2022) and PMBOK project-phase conventions.

Why construction OR matters

Scale of the problem · three anchor statistics

~13%
of global GDP is generated by the construction ecosystem — yet productivity has grown only ~1% per year over the last two decades, trailing every other major sector.
McKinsey Global Institute, Reinventing Construction (2017) · mckinsey.com
~9 in 10
major infrastructure projects blow through budget or schedule; cost overruns average ~27.6% in real terms, with a long right tail of “fat-tailed” disasters — a problem that motivated the RCPSP literature for six decades.
Flyvbjerg, B. (2014), Project Management Journal · doi:10.1002/pmj.21409
~37%
of global energy-related and process CO2 emissions come from buildings and construction — site-layout, earthmoving, and material-logistics optimisation are first-order sustainability levers.
UNEP & GlobalABC, 2022 Global Status Report for Buildings and Construction · globalabc.org

Decision framework

Four lenses on the same sixteen applications

The primary taxonomy crosses decision level (strategic — multi-project, multi-year; tactical — single-project planning and design; operational — day-to-week execution) with OR problem family (selection & location, scheduling & sequencing, resource & workforce, logistics & flow, finance & bid). The scheduling column is densely populated because construction-OR literature has concentrated there for decades — Hartmann & Briskorn (2022) catalogue more than 150 RCPSP variants alone. Dashed cells are honest gaps — decisions that exist in practice but are not yet modelled here.

Level ↓  ·  Family →
Select & Locatecombinatorial choice
Schedule & Sequencetiming under constraints
Resource & Workforcecrews, peaks
Logistics & Flowrouting, hauling, lot sizing
Finance & Bidmarkup, cash flow
Strategicmulti-project · 1–10 yr
Project Portfolio Selection 0-1 Knapsack Construction Site Selection UFLP
Gap · multi-project RCMPSP (active research frontier)
Gap · multi-year crew capacity planning
Gap · long-term equipment fleet sizing
Bid Markup Decision Friedman-Gates
Tacticalsingle project · pre-build
Site Layout Planning SLP / QAP
Project Scheduling RCPSP Time-Cost Tradeoff MRCPSP Stochastic RCPSP SRCPSP Linear / LOB Scheduling LSM Precast Scheduling Flow Shop
Crew Task Assignment GAP Resource Leveling RCPSP / min-peak
Material Procurement Wagner-Whitin
Cash Flow Optimisation Multi-period LP
Operationalday–week · execution
Gap · real-time workspace reallocation
Punch List Scheduling Pm || Cmax
Gap · daily dispatching & reassignment
Equipment Routing CVRP Earthmoving Optimisation Mass-haul LP
Gap · daily cash position & draw requests

The PMI PMBOK Guide organises every construction project into five process groups — initiation, planning, execution, monitoring/control, and closeout. Condensed for construction practice, this yields the five-phase flow below. Phase 2 (Planning & Design) is where most modelled decisions concentrate, reflecting the reality that it is cheaper to optimise on paper than on site.

1. Initiation& Feasibility
Portfolio Selection Knapsack Site Selection UFLP Bid Markup Friedman-Gates
2. Planning& Design
Project Scheduling RCPSP Time-Cost Tradeoff MRCPSP Stochastic RCPSP SRCPSP Resource Leveling min-peak Linear / LOB LSM Site Layout SLP / QAP Cash Flow LP Crew Assignment GAP
3. Procurement& Contracting
Material Procurement Wagner-Whitin Precast Scheduling Flow Shop
4. Execution& Construction
Equipment Routing CVRP Earthmoving Mass-haul LP
5. Closeout& Handover
Punch List Pm || Cmax

Construction-OR literature self-organises around a small number of parent problem classes, each with a deep variant tree. Hartmann & Briskorn (2010, 2022) catalogue the RCPSP family; the routing, selection, assignment, and financial branches have their own canonical surveys. Dashed nodes are active research frontiers not yet modelled on this site.

Scheduling
RCPSP — base single-mode Pritsker et al. 1969 · Blazewicz et al. 1983 MRCPSP — multi-mode / crashing Kelley 1961 · De et al. 1995 SRCPSP — stochastic durations Herroelen & Leus 2005 RCPSP/max — generalised precedence Discussed on RCPSP page RCMPSP — multi-project Open frontier · not built Pm || Cmax — parallel machines Graham 1969 Resource Leveling — min-peak / min-var Burgess-Killebrew 1962 · Harris 1978 LSM / LOB — location-based scheduling Harris & Ioannou 1998 Precast / modular production Chan & Hu 2002 · Leu & Hwang 2002
Routing & Flow
CVRP — capacitated vehicle routing Dantzig & Ramser 1959 · Clarke & Wright 1964 Mass-haul LP — earthmoving / cut-fill Easa 1988 · Marzouk & Moselhi 2004 Lot-Sizing — Wagner-Whitin DP Wagner & Whitin 1958 · Silver & Meal 1973
Selection & Location
0-1 Knapsack — project portfolio Archer & Ghasemzadeh 1999 UFLP — site selection Balinski 1965 · Cornuéjols et al. 1983 SLP / QAP — temporary facility layout Tommelein & Zouein 1993
Assignment
GAP — crew-to-task assignment Ross & Soland 1975
Financial Modelling
Bid Markup — Friedman-Gates Bayesian Friedman 1956 · Gates 1967 Cash Flow — multi-period LP Navon 1996 · Elazouni 2009

The same sixteen applications re-grouped by the primary stakeholder who actually makes the decision. Owners drive portfolio and site selection and set the bid context; general contractors own the master schedule, crewing, and cash flow; subcontractors and specialist trades execute crew- and equipment-level operations. Many applications have a natural secondary stakeholder — tagged below only by the primary.

Owner / Developer
Selects the project portfolio, secures the site, sets the bid context, and lives with the long-term cash position.
Portfolio Selection Knapsack Site Selection UFLP Bid Markup (owner RFP) Friedman-Gates Cash Flow (owner view) Multi-period LP
General Contractor
Owns the master schedule, resource plan, cash exposure, and integration of trades across the full project.
Project Scheduling RCPSP Time-Cost Tradeoff MRCPSP Stochastic RCPSP SRCPSP Resource Leveling min-peak Linear / LOB Scheduling LSM Site Layout SLP Material Procurement Wagner-Whitin Punch List Scheduling Pm || Cmax
Subcontractor / Specialist
Executes crew- and equipment-level operations, runs precast/modular shops, hauls earth, routes heavy equipment between sites.
Crew Task Assignment GAP Precast Scheduling Flow Shop Equipment Routing CVRP Earthmoving Optimisation Mass-haul LP

Application catalog

All sixteen pages · click a card to open the interactive solver

0-1 Knapsack Strategic
Project Portfolio Selection
Select which projects to pursue from a pipeline given limited capital, bonding capacity, and resources, maximising expected contribution margin.
Open solver
UFLP Strategic
Construction Site Selection
Choose where to locate a new project among candidate sites, balancing acquisition cost, permitting risk, accessibility, and market reach.
Open solver
Friedman-Gates Strategic
Bid Markup Decision
Choose the optimal markup on a tender bid under uncertainty about competitor behaviour, using Bayesian Friedman-Gates maximum-expected-profit logic.
Open solver
SLP / QAP Tactical
Site Layout Planning
Place temporary facilities (lay-down yards, site offices, crane pads, access roads) on a project site to minimise intra-site material and crew travel.
Open solver
RCPSP Tactical
Project Scheduling (RCPSP)
Assign start times to project activities under precedence constraints and renewable-resource limits to minimise project makespan — the canonical NP-hard formulation.
Open solver
MRCPSP Tactical
Time-Cost Tradeoff
Decide which activities to crash by switching to faster, more expensive modes to meet a deadline, tracing the time-cost Pareto frontier.
Open solver
SRCPSP Tactical
Stochastic RCPSP
Build robust schedules under uncertain activity durations using time-buffer insertion, proactive baseline plus reactive repair, or stochastic DP.
Open solver
LSM / LOB Tactical
Linear / LOB Scheduling
Schedule repetitive operations (highway paving, high-rise floors, pipeline segments) on a location-time diagram to keep crews working without interruption.
Open solver
Flow Shop Tactical
Precast Scheduling
Sequence precast / modular element production through casting, curing, and delivery to match the on-site erection schedule without buffer stockouts.
Open solver
GAP Tactical
Crew Task Assignment
Assign multi-skilled crews to tasks of differing productivity to minimise crew-cost while meeting schedule commitments and skill requirements.
Open solver
Resource Leveling Tactical
Resource Leveling
Smooth the manpower histogram of a feasible RCPSP schedule — reducing peak and variance — without extending the project deadline.
Open solver
Wagner-Whitin Tactical
Material Procurement Planning
Decide order quantities and timing across the project schedule to minimise the sum of fixed ordering and per-period holding costs while never stocking out.
Open solver
Multi-period LP Tactical
Cash Flow Optimisation
Smooth a contractor's monthly cash position through billing timing, front-loading, retainage release, and short-term credit — an LP over the project horizon.
Open solver
Pm||Cmax Operational
Punch List Scheduling
Sequence closeout punch-list items across parallel closeout crews to complete inspection turnover as fast as possible (parallel-machine makespan).
Open solver
CVRP Operational
Equipment Routing
Route flatbed trucks from a central yard to deliver heavy equipment to active job sites, respecting truck capacity and site delivery windows.
Open solver
Mass-haul LP Operational
Earthmoving Optimisation
Balance cut and fill volumes across a linear-works project to minimise total dirt-hauling distance — Bruckner's classical mass-haul diagram, now as an LP.
Open solver

Project lifecycle timeline

The chronological view · complementary to the decision matrix above

The same sixteen applications, laid out in the order they typically fire through a real construction project. Useful when the question is “what decisions am I making right now?” rather than “which OR problem family do I need?”.

1 · Portfolio & Feasibility

2 · Pre-Design

3 · Detailed Planning

4 · Pre-Build Procurement

5 · Crew & Equipment Staging

6 · Execution

7 · Closeout

Current research frontiers

Where construction OR is actively evolving

Stochastic & robust project scheduling

Activity durations in construction are chronically uncertain — weather, permits, subcontractor availability, material deliveries. Proactive-reactive scheduling (Herroelen & Leus 2005), chance-constrained RCPSP, and distributionally robust extensions remain the most active RCPSP research direction (Hartmann & Briskorn 2022).

BIM-integrated 4D / 5D scheduling & digital twins

Coupling CAD / BIM geometry with the schedule (4D) and cost (5D) enables clash detection, constructability feedback, and real-time progress telemetry. Digital twins close the loop — sensor data feeds back into live-updating RCPSP / resource-levelling models during execution.

Low-carbon & circular construction optimisation

Embodied-carbon minimisation in concrete mixes, earthwork balancing to cut haul distances, reverse-logistics for construction & demolition waste, and re-use of salvaged structural elements — all are being re-framed as multi-objective optimisation problems alongside cost and schedule.

Key references

Cited above · DOIs & permanent URLs

Hartmann, S., & Briskorn, D. (2010).
“A survey of variants and extensions of the resource-constrained project scheduling problem.”
European Journal of Operational Research, 207(1), 1–14. doi:10.1016/j.ejor.2009.11.005
Hartmann, S., & Briskorn, D. (2022).
“An updated survey of variants and extensions of the resource-constrained project scheduling problem.”
European Journal of Operational Research, 297(1), 1–14. doi:10.1016/j.ejor.2021.05.004
Kelley, J. E., & Walker, M. R. (1959).
“Critical-path planning and scheduling.”
Proceedings of the Eastern Joint Computer Conference, 160–173. (CPM origin, DuPont.)
Malcolm, D. G., Roseboom, J. H., Clark, C. E., & Fazar, W. (1959).
“Application of a technique for research and development program evaluation.”
Operations Research, 7(5), 646–669. (PERT origin, Polaris.) doi:10.1287/opre.7.5.646
Kelley, J. E. (1961).
“Critical-path planning and scheduling: mathematical basis.”
Operations Research, 9(3), 296–320. (Time-cost tradeoff original formulation.) doi:10.1287/opre.9.3.296
Pritsker, A. A. B., Watters, L. J., & Wolfe, P. M. (1969).
“Multiproject scheduling with limited resources: a zero-one programming approach.”
Management Science, 16(1), 93–108. (Canonical RCPSP formulation.) doi:10.1287/mnsc.16.1.93
Blazewicz, J., Lenstra, J. K., & Rinnooy Kan, A. H. G. (1983).
“Scheduling subject to resource constraints: classification and complexity.”
Discrete Applied Mathematics, 5(1), 11–24. (RCPSP NP-hardness proof.) doi:10.1016/0166-218X(83)90012-4
Brucker, P., Drexl, A., Möhring, R., Neumann, K., & Pesch, E. (1999).
“Resource-constrained project scheduling: notation, classification, models and methods.”
European Journal of Operational Research, 112(1), 3–41. doi:10.1016/S0377-2217(98)00204-5
Kolisch, R., & Sprecher, A. (1997).
“PSPLIB — a project scheduling problem library.”
European Journal of Operational Research, 96(1), 205–216. (PSPLIB benchmark set.) doi:10.1016/S0377-2217(96)00170-1
Kolisch, R., & Hartmann, S. (2006).
“Experimental investigation of heuristics for resource-constrained project scheduling: an update.”
European Journal of Operational Research, 174(1), 23–37. doi:10.1016/j.ejor.2005.01.065
Herroelen, W., & Leus, R. (2005).
“Project scheduling under uncertainty: survey and research potentials.”
European Journal of Operational Research, 165(2), 289–306. (Stochastic RCPSP anchor.) doi:10.1016/j.ejor.2004.04.002
Project Management Institute. (2021).
A Guide to the Project Management Body of Knowledge (PMBOK Guide), 7th ed.
PMI. (Life-cycle phases, process groups, and stakeholder taxonomy.) pmi.org/pmbok-guide-standards
Flyvbjerg, B. (2014).
“What you should know about megaprojects and why: an overview.”
Project Management Journal, 45(2), 6–19. (Cost / schedule overrun evidence.) doi:10.1002/pmj.21409

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