Custom Odoo Job Costing Module

I want to replace our spreadsheet-based job-costing sheet with a purpose-built Odoo add-on tailored for construction projects. The module must let me enter an estimate, record every real expense as the job unfolds, and watch the planned-vs-actual figures roll into a live profitability report for each project.

It has to speak natively with Odoo CRM so that a job opened from a lead or opportunity keeps the customer, site and contract details in one place. A very small prototype (models, a couple of views, no reporting yet) is available; you are free to refactor or start fresh as long as the final result fits cleanly into standard Odoo and installs with a single click.

Core requirements
• Cost estimation form that mirrors our current sheet (materials, labour, subcontract, plant, overheads).
• Automated capture of actual costs from vendor bills, timesheets and stock moves.
• On-screen and printable reports showing variance and gross margin per job.
• Seamless link to CRM records so we can launch a quote, convert it to a job and track the pipeline in one flow.

Deliverables
• Installable Odoo module (.zip or Git repo) with models, menus, security rules and QWeb/Excel export for reports.
• Demo data and clear setup notes so I can test on my own database.
• Brief hand-over call or video explaining key points in the code.

The simpler and more Odoo-native you keep it, the faster we can move to phase two (multi-company and inventory integration), so please tell me how you plan to structure the models and where you might reuse standard objects instead of reinventing them.