Product Requirements Document

Mobile Field Execution and Construction Estimating Architecture

Version: 1.0
Date: 2026-06-24

1. Product Foundations and Market Positioning

Platform Core and Architecture

This platform is an AI-powered field service and finance automation engine designed for trade contractors (HVAC, plumbing, electrical, etc.) to unify field operations with back-office financial ledgers. To ensure enterprise-grade scalability and rapid iteration, the platform is built on a Mendix-based low-code architecture, utilizing an offline-first mobile footprint to maintain operational continuity in zero-connectivity environments.

Target Market Segment

The system is optimized for high-volume, dispatch-centric service and construction trades, including:

• ▸Landscaping and Roofing
• ▸Mechanical (HVAC, Plumbing, Electrical)
• ▸General Contracting (GC)

Enterprise Scale and Adoption Criteria

The platform is engineered for organizations that have reached a specific operational maturity:

2. Mobile Field Execution & Offline Architecture

Native Mobile Infrastructure

The field experience is delivered via native applications designed for performance and security:

Offline-First Logic and Managed Dependencies

Operational reliability is maintained via offline-first logic execution using Nanoflows. This ensures that even during cellular signal loss, technicians can execute on-device logic and forms.

• ▸Managed Dependencies: Production environments behind firewalls utilize strict naming conventions for offline installers (e.g., adoptiumjdk_21_x64.msi for the compiler engine) to ensure consistent builds without internet access.
• ▸Data Integrity: Technicians can purge local media storage to free device space without deleting active job photos or forms, which remain cached until the next successful synchronization.

Security and Dispatch Protocols

• ▸Biometric Access (Version 6.0.0): Native implementation of biometric login (FaceID / TouchID) for secure field access. Technicians enable this via Settings > Security to enforce jobsite compliance.
• ▸Push Notification Framework (Version 6.0.7): Real-time work order dispatch and technician alerts are handled through a dedicated framework to ensure immediate responses to scheduling modifications.

3. Field Workflows & Timekeeping Mechanics

Mobile Operational Sequence

Timekeeping Modes

4. Construction Estimating & Calculation Engine

Plan-Based Takeoff and Estimation

Version 4.0.23 introduced the mobile project takeoff estimation tool. This allows estimators to build cost sheets directly from site requirements and project plans, ensuring that bids reflect real-world site conditions rather than generic pricebook averages.

Project Gross Margin ($M_g$) Engine

The platform utilizes a core mathematical formula to protect profitability during the estimation phase:

$M_g = \frac{R_p - (C_m + C_l + C_s)}{R_p}$

Commercial Rate Sheets

Client-specific pricing is configured through a four-stage setup:

1. ▸Permissions — Grant granular roles for "Calculate Prices" and "View Pricing Rates."
2. ▸Labor Services — Create labor items (e.g., Standard vs. Holiday) with empty price fields to allow for sheet-driven dynamic pricing.
3. ▸Payroll Mapping — Link labor types to payroll settings to ensure field hours translate to correct invoice line items.
4. ▸Master Sheets — Build contract-specific rules for material markups, equipment discounts, and hourly labor rates.

5. Change Order & Digital Compliance Workflows

Formal Change Order Lifecycles

To prevent "project creep" and unbilled labor, the platform standardizes formal change order lifecycles. By providing a structured documentation and approval loop for scope modifications, the system eliminates the revenue leakage common in manual workarounds.

MX Build Card and Spend Control

Integrated financial controls utilize the MX Build Card system to provide real-time margin protection:

• ▸Spend Limits: Administrators issue physical or virtual project-specific cards with strict spending limits.
• ▸AI Classification: Expenses are automatically classified into cost codes, preventing unauthorized overhead.
• ▸Margin Protection: In practice, this real-time control has enabled firms (e.g., Epic Wood Work) to identify and reject over $10,000 in incorrect transactions in a single month before funds left the account.

Digital Compliance

• ▸eSignatures: Accelerated bid conversion through integrated electronic signatures during the "Estimate & Proposal" phase.
• ▸Automated Documentation: Standardized workflows for joint checks, lien waivers, and unified audit trails to ensure legal and financial compliance across project timelines.

6. Technical Specifications & Performance Guardrails

Enterprise Deployment Resource Plans

The following specifications apply to Enterprise Private Cloud (Kubernetes / Tekton) deployments and are not adoption criteria for individual accounts:

Performance Best Practices & Guardrails

The platform utilizes the Best Practice Recommender tool to enforce the following architectural standards:

1. ▸Calculated Attributes — Avoid in favor of stored attributes updated via microflows to minimize runtime computational overhead.
2. ▸Indexing — Mandatory for entities exceeding 10,000 records, focusing on attributes used in XPath search and sort queries.
3. ▸Loop Execution — Database commits inside loops are forbidden. Objects must be collected in memory and processed in batches of 1,000 to minimize database locking.
4. ▸Access Rules — Security logic must be optimized by splitting entities into one-to-one associations to prevent slow, complex database queries.

CI/CD and Diagnostic Infrastructure

The compilation engine (MxBuild) generates the Software Bill of Materials (SBOM) in CycloneDX format.