Construction Planning and Site Operations Exercises

These exercises practise engineering calculations and decision checks used in construction planning and site operations. They focus on making constraints visible before they become field failures: incomplete work packages, unrealistic schedules, overloaded logistics, unchecked temporary loads, weak inspection evidence, and incomplete handover records.

Assume simplified nominal values unless an exercise states otherwise. Real construction planning must also follow the project contract, temporary-works procedure, design standards, site safety plan, environmental permits, inspection and test plan, commissioning requirements, and change-control process.

How to Use These Exercises

For each problem:

1. define the work package, site boundary, and decision being made;
2. separate schedule logic from resource capacity;
3. check whether temporary loads and temporary works are explicitly included;
4. connect numerical results to inspection, safety, environmental, or handover evidence;
5. state the operational action, not only the calculated value.

The most common mistake is treating the schedule as independent from engineering. A programme date is credible only if drawings, materials, workface access, inspections, temporary works, environmental controls, and field instructions are ready.

For each result, state whether it supports release, resequencing, workface protection, temporary-works hold, logistics change, quality correction, or refusal to close handover. Site calculations are useful only when they change a field decision before the work becomes hidden or irreversible.

Exercise 1: Work-Package Readiness

A concrete foundation work package requires eight constraints to be cleared before work starts:

• approved drawings;
• reinforcement delivered;
• formwork available;
• excavation accepted;
• groundwater control running;
• inspection hold point booked;
• concrete supplier confirmed;
• access route open.

Six of the eight constraints are currently cleared.

Find the readiness percentage and state whether the package should be released if the project rule requires all safety-critical constraints to be cleared.

Solution

Readiness percentage:

The package is not ready for release if any missing constraint is safety-critical or blocks inspection, access, temporary works, or quality evidence.

Engineering Comment

A readiness percentage is a useful signal, but it is not a release decision by itself. Missing groundwater control or inspection release is more serious than missing a noncritical administrative item. Construction planning should identify which constraints are hard gates.

Exercise 2: Critical Path for a Small Civil Sequence

A simplified activity network has the following logic:

Activity	Duration (days)	Predecessor
A: Mobilize	3	None
B: Excavate	5	A
C: Install drainage	2	B
D: Form and reinforce	4	B
E: Place concrete	1	C and D
F: Cure to release strength	7	E

Find the project duration and the controlling path.

Solution

Path through drainage:

Path through formwork and reinforcement:

The project duration is:

The controlling path is:

Engineering Comment

The drainage activity is important, but it is not critical under this logic. If drainage is delayed by more than two days, it can become critical because activity E cannot start until both C and D are complete.

Exercise 3: Weekly Plan Reliability

A site team committed to completing 10 tasks during the week. Seven were completed as planned. In the same look-ahead window, 12 upcoming tasks were reviewed and 9 had all constraints removed.

Find the percent plan complete and the constraint-readiness ratio.

Solution

Percent plan complete:

Constraint-readiness ratio:

Engineering Comment

The two numbers answer different questions. Percent plan complete measures reliability of commitments already made. Constraint readiness measures whether future work is being prepared. A site can appear busy while future work is quietly becoming unready.

Exercise 4: Crane Capacity as a Logistics Bottleneck

A site must move 48 palletized unit loads during an 8-hour shift. The gate can unload 6 pallets per hour. The crane can place 5 pallets per hour.

Identify the bottleneck and determine whether the shift capacity is sufficient.

Solution

Gate capacity:

Crane capacity:

The crane is the bottleneck because:

Time required at the crane rate:

Engineering Comment

The delivery plan is not feasible in one 8-hour shift unless the load count is reduced, crane rate increases, working time is extended, a second handling method is added, or the installation sequence changes. Otherwise pallets will accumulate and may block safe access.

Exercise 5: Material Storage Using Little’s Law

A facade package receives materials at an average rate of \lambda=18\ \text{pallets/day}. The average number of pallets stored on site is L=54.

Estimate the average time each pallet spends on site before installation. Then find the target average time if safe storage is limited to 36 pallets at the same arrival rate.

Solution

Little’s Law:

Current average time:

Target time for 36 pallets:

Engineering Comment

Reducing storage requires changing delivery cadence, installation rate, or package sequencing. It cannot be solved by asking crews to work around excess material if the workface, lifting equipment, or inspection flow remains unchanged.

Exercise 6: Temporary Construction Load Check

A temporary platform receives a nominal construction load of F_k=42\ \text{kN}. The temporary-works procedure uses a load factor \gamma_F=1.5. The checked support capacity for the stage is 58\ \text{kN}.

Find the factored load and the capacity margin.

Solution

Factored design load:

Capacity margin:

Engineering Comment

The negative margin means the stage should not proceed under these assumptions. Options include reducing the load, adding temporary support, changing the sequence, rechecking the actual load path, or obtaining an engineered redesign.

Exercise 7: Pre-Pour Inspection Defect Rate

A pre-pour inspection checks 80 items: reinforcement placement, cover, embeds, formwork condition, cleanliness, access, hold-point release, and concrete delivery readiness. Four nonconformances are found before placement.

Find the defect rate.

Solution

Defect rate:

Engineering Comment

A 5% defect rate before concrete placement is valuable information because the defects are still accessible. The engineering action is to classify severity, correct the findings, document release, and check whether the defects share a common cause such as drawing ambiguity, congested reinforcement, poor workface access, or rushed sequencing.

Exercise 8: Risk Priority Number for a Missed Hold Point

A failure mode is “concrete placed before reinforcement inspection release.” The initial rankings are:

A new interlock and release board reduce the occurrence ranking to O=3 and detection ranking to D=2.

Find the initial and revised risk priority numbers.

Solution

Initial:

Revised:

Reduction:

Engineering Comment

The reduction is meaningful only if the interlock changes real site behaviour. RPN is an ordinal screening tool, not a physical risk measure. High-severity failure modes still need engineered controls, stop-work authority, and evidence that the control is used.

Exercise 9: Dewatering Pump Reliability

A dewatering pump logs 600 operating hours during a basement excavation and has two functional failures. Total downtime for repair is 6 hours.

Find the observed MTBF, MTTR, and operating availability estimate.

Solution

Mean time between failures:

Mean time to repair:

Availability estimate:

Engineering Comment

The availability looks high, but consequence matters. A short dewatering failure during a critical excavation stage can still increase hydrostatic pressure, soften ground, interrupt concrete placement, or breach environmental discharge limits. Backup pumps and alarms may be justified even when average availability is acceptable.

Exercise 10: Handover Record Completion

A civil package requires 96 handover records. At review, 88 are accepted, 5 are pending, and 3 are rejected.

Find the accepted-record ratio and the unresolved-record count.

Solution

Accepted-record ratio:

Unresolved records:

Engineering Comment

The package is not fully validated while records are pending or rejected. The unresolved items may include tests, as-built drawings, concessions, commissioning evidence, material certificates, inspection releases, or corrective actions. Handover quality matters because future engineers rely on this evidence during maintenance, modification, and asset assessment.

Review Checklist

Before accepting a construction planning calculation, check:

• whether the work package has a defined boundary and acceptance evidence;
• whether critical path logic includes real predecessors, inspections, and temporary works;
• whether resource capacity is checked separately from schedule dates;
• whether storage, unit loads, crane time, access, and workface constraints are compatible;
• whether temporary construction loads are factored and stage-specific;
• whether quality controls happen before defects become hidden;
• whether RPN, MTBF, and availability are tied to consequence and controls;
• whether safety-critical constraints are treated as release gates rather than diluted inside readiness percentages;
• whether unresolved records are assigned to an accountable owner, due date, and acceptance criterion;
• whether handover records prove that the asset was built, tested, and accepted as intended.

Good construction planning is engineering under constraint. The calculation is useful when it changes a field decision before the work becomes unsafe, defective, delayed, or unverifiable.