delay-analysis

What this skill does

# Delay Analysis

## Overview

Analyze construction schedule delays for project recovery and claims. Perform time impact analysis (TIA), identify concurrent delays, calculate delay damages, and prepare documentation for dispute resolution.

> "Proper delay analysis is essential for fair resolution of construction disputes" — DDC Community

## Delay Analysis Methods

```
┌─────────────────────────────────────────────────────────────────┐
│                    DELAY ANALYSIS METHODS                        │
├─────────────────────────────────────────────────────────────────┤
│                                                                  │
│  As-Planned vs As-Built    │    Time Impact Analysis (TIA)      │
│  ─────────────────────     │    ────────────────────────────    │
│  Compare original to       │    Insert delay events into        │
│  actual schedule           │    schedule to measure impact      │
│                            │                                     │
│  Windows Analysis          │    Collapsed As-Built              │
│  ────────────────          │    ─────────────────               │
│  Divide project into       │    Remove delays from as-built     │
│  time periods              │    to find "but-for" completion    │
│                                                                  │
└─────────────────────────────────────────────────────────────────┘
```

## Technical Implementation

```python
from dataclasses import dataclass, field
from typing import List, Dict, Optional, Tuple
from datetime import datetime, timedelta
from enum import Enum
from collections import defaultdict

class DelayType(Enum):
    EXCUSABLE_COMPENSABLE = "excusable_compensable"      # Owner caused - time + money
    EXCUSABLE_NON_COMPENSABLE = "excusable_non_compensable"  # Neither party - time only
    NON_EXCUSABLE = "non_excusable"                      # Contractor caused - no relief
    CONCURRENT = "concurrent"                            # Both parties - complex

class DelayCause(Enum):
    OWNER_CHANGE = "owner_change"
    LATE_INFORMATION = "late_information"
    DIFFERING_CONDITIONS = "differing_conditions"
    PERMIT_DELAY = "permit_delay"
    WEATHER = "weather"
    LABOR_SHORTAGE = "labor_shortage"
    MATERIAL_DELAY = "material_delay"
    SUBCONTRACTOR = "subcontractor"
    COORDINATION = "coordination"
    ACCESS = "access"
    FORCE_MAJEURE = "force_majeure"

@dataclass
class DelayEvent:
    id: str
    description: str
    cause: DelayCause
    delay_type: DelayType
    start_date: datetime
    end_date: datetime
    affected_activities: List[str]
    responsible_party: str
    documented: bool = True
    supporting_docs: List[str] = field(default_factory=list)
    calculated_impact: int = 0  # days
    concurrent_with: List[str] = field(default_factory=list)

@dataclass
class ScheduleVersion:
    version_id: str
    version_type: str  # baseline, update, as-built
    data_date: datetime
    completion_date: datetime
    activities: Dict[str, Dict]  # activity_id -> {start, finish, duration}

@dataclass
class WindowPeriod:
    window_id: str
    start_date: datetime
    end_date: datetime
    planned_progress: float
    actual_progress: float
    delay_days: int
    delay_events: List[str]
    responsible_parties: Dict[str, int]  # party -> delay days

@dataclass
class DelayAnalysisReport:
    project_name: str
    analysis_date: datetime
    original_completion: datetime
    actual_completion: datetime
    total_delay: int
    excusable_delay: int
    non_excusable_delay: int
    concurrent_delay: int
    delay_events: List[DelayEvent]
    delay_by_cause: Dict[str, int]
    delay_by_party: Dict[str, int]
    recommended_extension: int
    potential_damages: float

class DelayAnalyzer:
    """Analyze construction schedule delays."""

    # Daily delay costs by project size
    DEFAULT_DAILY_COSTS = {
        "small": 5000,      # < $10M
        "medium": 15000,    # $10M - $50M
        "large": 40000,     # $50M - $200M
        "mega": 100000      # > $200M
    }

    def __init__(self, project_name: str, contract_completion: datetime):
        self.project_name = project_name
        self.contract_completion = contract_completion
        self.delay_events: Dict[str, DelayEvent] = {}
        self.schedule_versions: Dict[str, ScheduleVersion] = {}
        self.window_periods: List[WindowPeriod] = []
        self.daily_cost = self.DEFAULT_DAILY_COSTS["medium"]

    def set_daily_delay_cost(self, cost: float):
        """Set daily delay cost for damages calculation."""
        self.daily_cost = cost

    def add_schedule_version(self, version_id: str, version_type: str,
                            data_date: datetime, completion_date: datetime,
                            activities: Dict[str, Dict]) -> ScheduleVersion:
        """Add schedule version for analysis."""
        version = ScheduleVersion(
            version_id=version_id,
            version_type=version_type,
            data_date=data_date,
            completion_date=completion_date,
            activities=activities
        )
        self.schedule_versions[version_id] = version
        return version

    def add_delay_event(self, id: str, description: str,
                       cause: DelayCause, delay_type: DelayType,
                       start_date: datetime, end_date: datetime,
                       affected_activities: List[str],
                       responsible_party: str,
                       supporting_docs: List[str] = None) -> DelayEvent:
        """Add delay event for analysis."""
        event = DelayEvent(
            id=id,
            description=description,
            cause=cause,
            delay_type=delay_type,
            start_date=start_date,
            end_date=end_date,
            affected_activities=affected_activities,
            responsible_party=responsible_party,
            supporting_docs=supporting_docs or []
        )
        self.delay_events[id] = event
        return event

    def perform_as_planned_vs_as_built(self) -> Dict:
        """Perform As-Planned vs As-Built analysis."""
        baseline = self.schedule_versions.get("baseline")
        as_built = self.schedule_versions.get("as_built")

        if not baseline or not as_built:
            raise ValueError("Need baseline and as-built schedules")

        total_delay = (as_built.completion_date - baseline.completion_date).days

        # Analyze each activity
        activity_delays = []
        for act_id, baseline_act in baseline.activities.items():
            if act_id in as_built.activities:
                as_built_act = as_built.activities[act_id]

                baseline_finish = baseline_act['finish']
                actual_finish = as_built_act['finish']

                if isinstance(baseline_finish, str):
                    baseline_finish = datetime.fromisoformat(baseline_finish)
                if isinstance(actual_finish, str):
                    actual_finish = datetime.fromisoformat(actual_finish)

                delay = (actual_finish - baseline_finish).days

                if delay > 0:
                    activity_delays.append({
                        'activity_id': act_id,
                        'planned_finish': baseline_finish,
                        'actual_finish': actual_finish,
                        'delay_days': delay
                    })

        return {
            'method': 'As-Planned vs As-Built',
            'baseline_completion': baseline.completion_date,
            'actual_completion': as_built.completion_date,
            'total_delay': total_delay,
            'activity_delays': sorted(activity_delays, key=lambda x: -x['delay_days'])
        }

    def perform_time_impact_analysis(self, delay_event_id: str) -> Dict:
        """Perform Time Impact Analysis for specific delay event."""
        if delay_event_id not in self.delay_events:
            raise ValueError(f"Delay event {delay_event_id} not found")