HIGHLAND TOWERS TRAGEDY REVISITED

Credit : Astro Awani

Disclaimer

This article is a technical synthesis prepared for informational and educational purposes only. All explanations, timelines, interpretations, and engineering assessments in this document are derived from open and publicly accessible sources, including news reports, academic papers, task‑force summaries, legal documents, and published case studies.

This article does not represent, quote, or replace any official government report, forensic investigation report, or authoritative findings issued by relevant Malaysian agencies, professional bodies, or courts.

The analysis is prepared from a civil, structural, and geotechnical engineering perspective, with supplementary notes on regulatory and administrative processes, strictly for general understanding. It may simplify or generalize certain technical aspects and should not be used as a substitute for professional engineering judgement, legal advice, or regulatory compliance.

While every effort has been made to ensure accuracy, errors or omissions may exist, and interpretations may differ from official positions. Any use of any contents derived from this article is at the reader’s own discretion and responsibility.

Block 1 of the Highland Towers condominium (Ulu Klang, near Bukit Antarabangsa) collapsed on 11 December 1993 after a large, retrogressive landslide behind the building pushed the foundations and destroyed a retaining structure, the slide was the product of hillside clearance/over-development, failed drainage/diversion works and inadequate slope design/maintenance. 48 people died

1) Short timeline/Project Background

Highland Towers was built in phases in the 1970s–early 1980s at the foot of a steep, terraced hill in Taman Hillview / Ulu Klang. Block 1 (the southern block) is the one that collapsed.

In the early 1990s the Bukit Antarabangsa hilltop behind Highland Towers was developed (new roads, houses and earthworks). That development involved extensive cutting, vegetation removal and installation of diversion/drainage works (the “East Stream” diversion pipe is repeatedly mentioned in accounts). Heavy/repeated rain in December 1993 then triggered progressive slope failure. 

On 11 Dec 1993 the down-slope movement and failure of retaining works/earth mass undermined the piled foundations/rail-pile system behind Block 1; the block moved, fractured and collapsed. Rescue recovered 2 survivors and 48 fatalities.

2) Possible Engineering and Technical Root Causes

Several post-incident theories (later refuted) theorized that:

wastewater and greywater did not discharge properly into designated drains, leading to seepage and percolation into the subsurface soils behind Block 1. Over time, this may have softened the foundation soils, increased moisture content, reduced effective stress, and compromised pile stability. While not the primary confirmed trigger, personally I feel that this factor despite a good theory should be taken into account as a plausible contributing mechanism that exacerbated overall ground saturation and instability.

The following causes; however; are the commonly agreed, evidence-based causes cited by geotechnical studies and task-force reviews:

• Slope destabilisation from hilltop development and vegetation removal - Clearing and terracing reduced root strength, changed surface runoff and exposed slopes to erosion during heavy rain,

• Inadequate drainage and failed diversion pipe(s) - Diversion/pipe systems carrying the east creek and surface runoff either were under-designed, poorly installed or ruptured; water ingress and seepage into the slope greatly reduced soil shear strength and caused progressive erosion. Accounts point to burst diversion pipes and uncontrolled flow of silt, debris and water down the slope,

• Failure of retaining works / shallow support systems - Retaining walls and “raker/rail” piles used behind the car-park/retaining zones were unable to resist the lateral mass of saturated soil. Some authors point to inadequate design for lateral soil loads and progressive undermining of foundations,

• Inadequate site investigation and design assumptions - Subsequent case studies say geotechnical investigations, soil testing and slope stability analysis were insufficient or not conservative enough for the hillside conditions, thus, designs did not properly account for heavy rain pore pressure buildup and retrogressive failure mechanisms,

• Progressive (retrogressive) landslide mechanism - Once a lower portion failed (retaining wall/toe), the failure propagated upslope, moving very large volumes of saturated soil/mud that pushed on foundations (estimates in popular accounts describe huge volumes) and caused structural collapse. 

Put simply: water + unstable cut slope + insufficient drainage + inadequate retaining/foundation design = a retrogressive landslide that overloaded and undermined building foundations.

AI Generated Image - Simple Schematic - Not to Scale

3) Possible Institutional, Procedural failures 

During that time, the technical failures occurred in an environment of regulatory weakness, poor coordination and weak enforcement :

• Approvals without adequate hillside safeguards - Reviews after the event emphasised that state and local approvals allowed hillside development without consistent application of proper safeguards, guidelines or independent verification. The Malaysian Bar Task Force and subsequent studies list lack of compliance checks, inadequate planning procedures and approvals granted without sufficient technical oversight,

• Poor monitoring and maintenance - Drains, diversion pipes and retaining facilities require ongoing inspection and maintenance; the task force cites poor maintenance of drains/retaining walls and failure to act on residents’ complaints or visible signs,

• Fragmented responsibilities and weak verification of competence - The Task Force highlighted poor communication among developers, consultants, local authorities and state agencies and lack of independent verification of safety aspects for hillside works,

• Enforcement limits and legal immunity issues - In subsequent litigation the Ampang Jaya Municipal Council (MPAJ) was at first held to have some pre-collapse liability in lower courts, but the Federal Court later ruled (2006) that the local council was immune under provisions of the Street, Drainage and Building Act (SDBA) for “approval and inspection” functions, a significant legal outcome that limited civil claims against the local authority. That judgment shaped the legal aftermath and discussion about local authority duties. 

4) Authorities and Parties Involved

• Local authority (MPAJ at the time) : issues site approvals, inspects stormwater/drainage and enforces building codes. Investigations and the Task Force later criticised approval practice and monitoring but in litigation MPAJ successfully invoked limited immunity for its regulatory functions,

• Jabatan Kerja Raya (PWD) : involved in slope/road infrastructure and (later) commissioned government inquiries into Bukit Antarabangsa landslides. The Task Force referenced a federal JKR investigation whose full public release was an issue at the time,

• Landowners, developers, consulting engineers : the main parties responsible for safe design, correct earthworks, proper drainage and supervision. Civil suits were pursued against developers, engineers and other private parties. The technical reviews criticise competence and execution at the development level,

• Department of Environment (DOE) and Department of Occupational Safety & Health (DOSH)? : At the time, DOE is normally concerned with environmental impact, erosion control and consent conditions while DOSH at the time focuses on workplace safety (less central to a post-occupancy landslide, but relevant for construction phase safety). Public records and the Task Force emphasis focus mainly on planning, JKR and local council responsibilities (rather than DOSH actions in the disaster’s immediate technical causes, most published technical reviews do not place DOSH at the centre of the collapse causes as the original OSHA 93 was still at its' infancy stage (where the author was involved in the (unofficial) translation of the Parliament handsard in the consultancy capacity serving an Australia-Malaysia JV Safety Consultant)

5) Aftermath

Lawsuits followed - banks and some defendants settled with homeowners. The Federal Court ruling on MPAJ’s immunity (2006) was a landmark - it limited claims against local authorities for pre-collapse regulatory actions, which in turn shaped how liability is apportionable in Malaysia. 

The tragedy triggered repeated public and professional calls for better hillside development guidelines, stricter geotechnical standards, improved drainage and monitoring and clearer institutional responsibilities, many of which were reflected in later regulations, guidelines and the Task Force recommendations. 

6) Lessons Learned 

Practical recommendations that come from the literature and task-force reviews:

• Require competent, independent geotechnical investigation and slope stability analysis for all hillside works; design conservatively for worst-case rainfall/pore pressure,

• Do not allow unchecked top-cutting/overdevelopment without robust retaining systems, positive drainage and a mandatory maintenance plan,

• Insist on durable, inspected drainage/diversion works (pipes, gutters, culverts), surface runoff must not be allowed to concentrate onto or into slopes,

• Improve inter-agency coordination (local councils, JKR/DID, DOE - now known as OSC) and make roles/responsibilities and enforcement clear. 

• Implement slope monitoring, early-warning (movement, pore pressure) and community reporting channels so warning signs trigger action,

7) Short caveats about sources and remaining uncertainties

Multiple technical reviews and academic case studies (UM/UMP theses, research papers) analyze the geotechnical mechanisms; the Malaysian Bar Task Force collated legal and regulatory problems. Some government inquiry reports were not widely released at the time, and some fine technical details (exact pipe locations, as-built details of the retaining pile system) are reconstructed from expert testimony and post-event studies rather than a single public forensic report. 

8)  Other Tragedies

It's important to mention that there have been other incidents at the surroundings after the Highland Towers tragedy :

a) Taman Hillview landslide (20 Nov 2002) : A slope failure in Taman Hillview destroyed a bungalow and killed 8 people. Investigations indicated re-activation of an old landslide/filled zone.

Engineering summary: deep-seated re-activation of an earlier slide mass and unstable fills; local drains and slope materials were friable and became saturated after heavy rainfall/runoff concentration. The incident occurred only a few hundred metres from the Highland Towers site, showing persistent area vulnerability. 

b) Bukit Antarabangsa/Taman Bukit Mewah landslide (6 Dec 2008) : A large landslide destroyed multiple houses and killed several people (reports vary: 4–5 fatalities reported in multiple sources). The failure affected a wide swathe of slope (tens to a hundred metres scale).

Engineering summary: classified by investigators as a deep-seated landslide with a large crown width and significant depth; mechanisms included prolonged/intense rainfall, slope cutting/filling and poor retaining/foundation for slope toes. The failure measurements recorded (crest width, length, depth) are consistent with a deep, translational/rotational mass movement rather than a small local slip.

c) Numerous smaller but significant slides and reactivations (1993–2010s) : Multiple smaller incidents, slope reactivations and failures have been recorded across Ulu Klang/Bukit Antarabangsa (research reports and the Malaysian Bar Task Force catalogue dozens of events and many remediation works). Several caused property loss and some caused fatalities over the years. 

Engineering summary: many were rainfall-triggered, involved cut/fill zones or old landslide scars, and were aggravated by obstructed or misdirected drainage, poor retaining-wall construction (rubble or inadequately anchored walls), or the presence of loose fill materials. Research reviews count multiple major incidents in the area across two decades and emphasise recurring weaknesses in hillside approvals and maintenance. 

9) Recurring Technical Themes (why these keep happening)

• Rainfall + infiltration/pore pressure: Many failures were rainfall-triggered; prolonged or intense rain increases pore water pressure, reducing effective stress and shear strength of residual or fill soils. This is the proximate trigger in most cases,

• Human modification of slopes: Hill cutting, terracing, filling of gullies and vegetation removal changed the hills’ natural equilibrium and often created vulnerable geometry (steep free faces, overloaded benches),

• Inadequate or failed drainage/diversion works: Under-designed, clogged, ruptured or poorly maintained surface and subsurface drainage concentrated flow or allowed seepage into slopes, a common aggravating factor,

• Use of weak fills and poor retaining practice: Poorly compacted fill, rubble walls and non-engineered toe supports were repeatedly implicated. Deep seated failures often involve weak layers or interfaces beneath fills,

• Insufficient geotechnical investigation and oversight: Repeated studies call out limited site investigations, complacent assumptions about soil strength and lack of independent peer review for high-risk hillside works. 

9) Institutional/Regulatory Pattern

After each major failure there were reviews, task-forces and recommendations but published audits (and later events) suggest incomplete implementation, fragmented agency responsibilities and enforcement gaps (per Malaysian Bar Task Force and academic reviews).

10) Quick engineering implications/actions takes

• Treat the whole Bukit Antarabangsa/Taman Hillview area as high-risk: require full geotechnical reinvestigations and monitoring for any new works,

• Inspect and rehabilitate all drainage/diversion conduits: ensure positive discharge away from slopes,

• Replace or underpin weak retaining systems and replace loose fill with engineered solutions (anchors, deep piles, drained retaining systems),

• Enforce independent peer review, maintenance bonds and continuous monitoring (piezometers, inclinometers, rainfall thresholds & alarm/evacuation triggers). 

BUILDING A SUSTAINABLE FUTURE : ESG IN THE CONSTRUCTION INDUSTRY

Photo Credit : QHSEL Website

The construction industry is one of the world’s largest contributors to greenhouse gas (GHG) emissions, resource consumption, and waste generation. In today’s global business environment, Environmental, Social, and Governance (ESG) principles are becoming essential for sustainable development, risk mitigation, and long-term value creation in construction projects.

1) Environmental Responsibility

Construction activities can have significant environmental impacts - energy consumption, carbon emissions, water usage, and soil disturbance. By adopting ESG practices, companies can implement measures:

• Using low-carbon/recycled construction materials.
• Implementing energy-efficient machinery/renewable energy sources on-site.
• Applying water management and reduction plans.
• Incorporating green building designs that minimize the carbon footprint.

Simulated Case Study: ABC Construction Sdn. Bhd. undertook a mid-sized residential project in Malaysia. Through ESG-aligned practices, the company opted for precast concrete elements to reduce material waste, used solar-powered lighting on-site, and established a strict water runoff management system. As a result, carbon emissions were reduced by an estimated 20%, and water usage dropped by 15% compared to traditional construction methods.

2) Social Responsibility

The ‘S’ in ESG emphasizes people - workers, communities, and stakeholders. 

Construction companies can: 

• Ensure worker safety and fair labor practices.
• Engage local communities to minimize social disruption.
• Promote diversity and inclusion in hiring practices.

In the ABC project, the company implemented robust occupational health and safety protocols, conducted monthly community engagement sessions, and trained local workers in new construction technologies. This strengthened community relations and improved employee morale.

3) Governance

Strong governance ensures transparency, accountability, and ethical conduct. 

Construction firms should:

• Maintain clear policies on anti-corruption and compliance.
• Implement project monitoring and reporting systems.
• Establish ESG performance KPIs linked to executive compensation.

ABC Construction adopted a digital reporting system to monitor ESG metrics in real-time, allowing the management team to track environmental targets, safety incidents, and supplier compliance. This transparency boosted investor confidence and positioned the company as a responsible market leader.

Conclusion

Integrating ESG principles into the construction industry is no longer optional - it is a strategic imperative. Companies that proactively embed ESG into their projects can reduce environmental impact, foster positive social outcomes, and enhance governance practices. The ABC Construction case demonstrates that ESG-aligned approaches are practical, measurable, and capable of delivering both financial and societal value.

PM 101 CRITICAL PATH METHOD - NIK ZAFRI

The Critical Path Method (CPM) is a project scheduling technique used to identify the sequence of activities that determine the shortest possible duration to complete a project.

The Critical Path itself refers to the longest continuous chain of dependent activities from project start to finish.

Each activity on this path has zero float/slack, meaning any delay in these activities will directly delay the entire project.

Thus : The Critical Path is the backbone of the project timeline.

1.0 WHY IS IT IMPORTANT?

a. Time Control

It tells you the minimum completion time and helps the team prioritize work. Activities on the critical path must be closely monitored.

b. Resource Allocation

It helps planners allocate labour, equipment, and materials efficiently to critical activities first avoiding idle resources or bottlenecks.

c. Progress Tracking

It allows the project manager to know exactly which delays matter most — not all delays affect the overall completion date.

d. Decision-Making

In case of unforeseen issues (e.g., weather delays, material shortages), managers can quickly decide where to fast-track or crash the schedule to recover lost time.

e. Client and Contractor Communication

The critical path schedule provides a transparent, evidence-based tool for reporting progress, negotiating time extensions, or substantiating delay claims.

2.0. MISTAKES

a. No CPM - Depending Only on Bar Chart (Gantt Chart)

Many contractors rely solely on simple Gantt charts without logic links between activities.

You can’t identify dependencies or determine which tasks truly control the project completion.

This leads to poor coordination, unrealistic timelines, and misleading progress updates.

b. Incorrect Activity Sequencing

If the logic (predecessor-successor relationship) is wrong, the identified critical path will be inaccurate.

e.g. Installing formwork is shown as independent of rebar placement, this breaks the logical flow.

c. Unrealistic Durations

Setting durations without considering actual productivity, site conditions, or resource limits will distort the path.

The CPM might show a “fake” critical path that doesn’t match real-life constraints.

d. Ignoring Resource Constraints

A CPM schedule that ignores the availability of manpower, equipment, or materials gives a misleading view of feasibility.

e. CPM not updated

Failing to regularly update progress (weekly/monthly) means the CPM becomes obsolete. The project team loses sight of the real critical path as conditions change.

f. Too Many or Too Few Activities

Over-detailed CPMs become cumbersome, while oversimplified ones miss critical logic - both make tracking difficult.

g. Not Incorporated into the Master Work Program

Sometimes CPM is prepared separately and not aligned with the master work program or baseline schedule.

This results in inconsistent reporting, claim disputes, and confusion between stakeholders.

3.0 RISKS - WITH POOR CPM OR NO CPM AT ALL

• Inability to forecast completion date accurately.
• Increased risk of cost overruns and claims.
• Miscommunication between client, consultant, and contractor.
• Ineffective monitoring - site teams don’t know what to prioritize.
• Difficulty in granting or defending Extension of Time (EOT).
• Loss of credibility with the client and project financiers.

4.0 BEST PRACTICES

• Use CPM software (e.g., Primavera P6, MS Project) with correct logic links.
• Base the durations on historical productivity rates and resource availability.
• Update CPM regularly and review float changes.
• Align CPM with the Master Work Program (MWP).
• Conduct periodic schedule reviews with all stakeholders.
• Identify opportunities for fast-tracking or crashing early if delays arise.

5.0 EXAMPLES

Let me walk through a simplified example of how the Critical Path works in a construction sequence.

Project : Building a Simple Two-Storey Structure

How CPM Helps Here

The project manager now knows that Walls & Plastering (G) is a critical activity not Roof (F) or M & E (H). If delays occur in roof work, the project can still finish on time, but wall/plaster delay will push the completion date. Hence, site resources can be prioritized for critical path tasks to prevent overall delay.

Visual CPM Network Diagram

Below is a ready-to-use sample Master Work Program (MWP) for a small building project that includes CPM calculations, plus a revised schedule showing the effect of a delay and a footnote/legend explaining delay types and how to present them in the MWP.

• Baseline activity table (with ES, EF, LS, LF, float) - CPM forward/backward pass shown implicitly in the numbers.
• Baseline Critical Path.
• Revised schedule after a 4-day delay to a critical activity (showing how completion shifts).
• Footnotes - Legend explaining delay types, columns, and how to present delays/claims in the MWP.

Baseline Master Work Program (CPM included)

Assume day counting starts at Day 0 (project start). All arithmetic is shown as totals so you can verify calculations.

a) How these numbers were obtained (summary of forward/backward pass)

Forward pass (ES → EF)

ES of a node = max(EF of all predecessors).

e.g - ES(I) = max(EF(F), EF(G), EF(H)) = max(43, 46, 44) = 46 → EF(I) = ES(I) + 5 = 51.

Backward pass (LF → LS)

LF of a node = min(LS of all successors).

e.g. LF(E) = min(LS of F, G, H) = min(39, 36, 38) = 36 → LS(E) = LF(E) − 6 = 30.

Float = LS − ES (or LF − EF)

• Baseline Project Duration = EF(J) = 53 days.
• Baseline Critical Path (zero float activities):

A → B → C → D → E → G → I → J (total 53 days)

b) Revised work program (after the 4-day delay on G)

New project duration = 57 days. Delay = 4 days (equal to the G delay) because G was critical.

c) Footnote / Legend : showing delays and how to present them in the MWP

Columns used (and how to report)

• ES / EF : Early Start / Early Finish (forward pass).
• LS / LF : Late Start / Late Finish (backward pass).
• Float : LS − ES (slack). If float = 0 → critical.

Actual Start and Actual Finish (in your live MWP, add columns) - record real progress. Compare actual vs baseline.

d) Types of Delay (legend) - short definitions and examples relevant to construction

• Excusable, Non-Compensable Delay : Delay outside contractor’s control for which time extension may be granted but no money (e.g., unusually severe weather). Mark as E-NC.

• Excusable, Compensable Delay : Delay caused by the employer/client (e.g., late variations/instructions, late approvals, late design) - contractor gets EOT and additional cost (E-C).

• Non-Excusable Delay : Contractor’s fault (e.g., poor planning, labour shortage due to contractor’s hiring failure) : contractor liable for EOT denial and possible liquidated damages (NE).

• Concurrent Delay : Two or more delays happening at the same time where at least one is employer’s and one contractor’s; entitlement is complex and often needs separate forensic analysis (CONC).

• Acceleration/Owner-Directed Acceleration - Owner asks contractor to compress schedule; if owner-directed, costs may be compensable (ACC).

e) How to show delays in the MWP (recommended columns and notes)

• Baseline ES/EF : original planned.
• Current Forecast ES/EF : recalculated every update cycle (weekly/bi-weekly).
• Actual Start/Actual Finish : daily/weekly progress entries.
• Variance (days) - Current Forecast EF(J) − Baseline EF(J). (Shows total delay)

f) Delay Type : use legend codes (E-NC, E-C, NE, CONC).

i) Supporting Docs : RFI no., delivery note, weather log, employer instruction no., photos, site daily logs. Always attach proof for claims.

ii) Color / formatting convention (suggested):

• Red row = activity on the current critical path.
• Yellow cell = activity experiencing a delay.

Column for “Claim / EOT requested” with date and amount (if applicable).

g) Practical tips for your MWP + CPM on construction projects

• Baseline and Updates: Keep a clear baseline schedule (approved) and publish regular updates (weekly/fortnightly). Each update must include actual start/finish, and a recalculated CPM (forward/backward pass).

• Resource-aware CPM: CPM assumes unlimited resources; if your site is resource-constrained, overlay a resource-levelling run or show resource conflicts separately.

• Maintain Audit Trail: For every delay mark, attach contemporaneous evidence: delivery tickets, RFIs, site weather logs, photos, signatures. This is essential for EOT or claims.
  
  
• Identify Recovery Options Early: If a critical activity is delayed, evaluate crashing (add labour/equipment) or fast-tracking where technically safe - capture cost vs time trade-off.

• Watch for Hidden Critical Paths: Frequent logic checks - wrong links create wrong critical path. Keep activities at an appropriate level of detail (not too coarse, not too granular).

• Be explicit about calendars: Use the same work calendar (public holidays, weekends) when computing durations and ES/LS dates.

6.0 CONCLUSION

In construction, time is not just money, it’s control, credibility, and coordination. The Critical Path Method (CPM) remains the backbone of effective project scheduling because it identifies where time truly matters. Through a well-prepared CPM-based Master Work Program, project teams can visualize the entire construction process, anticipate bottlenecks, and make informed decisions when challenges arise.

Conversely, projects without a proper CPM analysis often fall prey to confusion, miscommunication, and costly delays. Without understanding which activities drive the completion date, both contractors and clients risk losing grip over schedule integrity, resource planning, and even contractual entitlements such as Extension of Time (EOT).

Ultimately, mastering the CPM is not just about software proficiency - it’s about discipline, foresight, and accountability. It empowers project stakeholders to act on facts rather than assumptions, ensuring that every day on site contributes toward successful, timely delivery.

GOOD AND SAFE PRACTICE IN CONSTRUCTION - ANOTHER OF NIK ZAFRI'S EXPERIENCE

Not a very long time ago, during my assessment visit to a growing construction company, I encountered a case that genuinely stood out as an example of proactive and correct action in construction management.

The project team faced a critical situation. After heavy rainfall, the excavation site for the basement structure began showing early signs of soil movement at the shoring wall.

Instead of waiting for further instructions or downplaying the risk, the team immediately halted all adjacent works, carried out a geotechnical review, and reinforced the shoring with additional struts and soil nails. More importantly, they resequenced the construction activities to reduce loading near the affected area while awaiting third-party verification.

What impressed me most was not only the speed of their technical intervention but also their integrated approach:

1) Risk Management - They documented the incident, conducted a mini risk re-assessment, and updated their risk register to prevent recurrence,

2) Safety Priority - Workers were evacuated from the affected area without delay, avoiding potential injury,

3) Stakeholder Communication - Within the same day, they notified the client, consultant, and authorities with a clear action plan, avoiding confusion or finger-pointing,

4) Long-term Solution - Instead of applying only temporary fixes, they incorporated permanent soil stabilization measures into the final design.

In the meeting, as the assessor, I highlighted that this was precisely the kind of culture and decision-making we expect in construction - swift, evidence-based, and prioritizing both safety and sustainability.

It was refreshing to see a team not just reacting to a problem but turning a risk into an opportunity to improve design and methodology.

Learning Through Observation and Demonstration

Photo Credit : The Edge

Construction workers, particularly foreign laborers, often acquire skills through practical exposure rather than formal training. By engaging daily in trades such as concreting, bricklaying, carpentry, plumbing, welding, and fitting, they gradually develop proficiency through observation, demonstration, and repetition. Over time, this experiential learning enables them to estimate dimensions, quantities, and material requirements instinctively, without relying on complex calculations.

Upon returning to their home countries, I heard and seen many of these workers apply their accumulated experience to build their own homes. Their competencies reflect a form of tacit knowledge, skills that are learned on-site, practiced repeatedly, and reinforced through problem-solving in real construction settings.

Notable characteristics of this learning process include:

1) Skill transferability - Techniques learned in one environment can be adapted to new and unfamiliar contexts,

2) Efficiency and intuition - Routine work cultivates an instinctive understanding of materials, tools, and processes,

3) Resourcefulness - Limited resources encourage creative solutions using locally available materials,

4) Self-reliance - Workers become independent builders capable of managing entire construction tasks,

5) Community contribution - Many extend their skills beyond personal use, contributing to family and community projects.

This demonstrates the effectiveness of experiential learning in developing practical expertise, particularly in labor-intensive industries like construction.

(Ironically, this is also my method of learning some trades in construction as well)

S-CURVE (CONSTRUCTION) COMMON ERRORS - BY NIK ZAFRI

One of the most common errors when preparing an S-Curve for construction projects is treating it as a “decorative” chart rather than a dynamic, data-driven planning tool. When that happens, the curve ends up being inaccurate, misleading, or impossible to use for tracking actual progress against the plan.

1. Using unrealistic baseline durations

a. Error: Tasks in the schedule are compressed or overlapped without proper resource leveling, producing a steep and optimistic S-Curve.

b. Scheduling Impact: The unrealistic baseline means early slippage will appear minimal at first, but delays will compound rapidly in later stages, making recovery nearly impossible.

c. Costing Impact: Overly aggressive timelines often lead to higher overtime, increased subcontractor rates, and higher procurement costs when trying to “catch up.”

2. Incorrect weighting between activities

a. Error: Assigning equal or arbitrary weight to all activities rather than basing them on actual cost or work volume.

b. Scheduling Impact: Progress reporting becomes skewed, a minor, low-cost activity might appear as significant as a major structural milestone.

Costing Impact: Budget tracking will be distorted, hiding cost overruns in major work packages until much later, when corrective action is more expensive.

c. Costing Impact: Budget tracking will be distorted, hiding cost overruns in major work packages until much later, when corrective action is more expensive.

3. Failing to align cash flow curve with physical progress

a. Error: The financial S-Curve (cash flow) is plotted independently from the physical progress S-Curve without syncing the timing of expenditures with actual work completion.

b. Scheduling Impact: The project may appear “on schedule” in physical terms but behind in financial terms, or vice versa, leading to confusion in stakeholder reporting.

c. Costing Impact: This misalignment often causes liquidity issues, paying too early for materials or subcontractors before the related work is completed, or underestimating cash requirements during peak activity periods.

These errors sometimes occur because the creation of the S-Curve is not shared collaboratively, becoming a “one-person show” (with the Project Manager often being the usual "victim")

In well-managed projects, the S-Curve is not “owned” by just one person, it’s a collaborative output:

a) Planner = timeline accuracy

b) QS/Cost Engineer = budget accuracy

c) Project Controls/Coordination = integration and reporting

c) PM = accountability