We are a growing UK-based company operating two distinct HVAC brands from a single Odoo Online (v19) database: Brand 1: Domestic Gas and Heating. Brand 2: Domestic and Commercial Air Conditioning and Refrigeration. Our current team consists of 3 lead engineers plus trainees. We receive leads from various online sources and also carry out subcontract work for larger companies (BOXT, Checkatrade, Rightio). Project Overview & Constraints: We want a full redesign of how we use Odoo to run our entire operation. We are using Odoo Online v19. We have Odoo Studio, but NO custom code or 3rd-party apps are allowed. We will use Odoo’s native storage/chatter for all customer records and photos. Budget Strategy: We are working with a strict budget. Therefore, this massive project will be executed over a long period of time across clearly defined, fixed-price milestones. Phase & Deliverable Breakdown: Milestone 1: CRM, Lead Management & Sales/Purchase Routing Automated & Manual Leads: Use Zapier to route automated leads (Bark, Facebook, Website) into CRM, tagged by Brand. Create a streamlined internal SOP/workflow for staff to manually input un-automatable leads (MyBuilder, etc.). Subcontractor Workflow: Design a process for jobs where we are the subcontractor (e.g. BOXT is the customer paying us, but the service address is a residential homeowner). Sales to RFQ Routing: Configure standard Odoo routes (MTO/Buy/Replenish) so that when we quote a customer for a product or "Kit" (e.g., a boiler plus specific parts), the system automatically breaks it down and generates Draft RFQs for our suppliers. Milestone 2: Field Service, Worksheets & Timesheets Scheduling: Set up Field Service and Calendar to manage the lifecycle: 1. Site visit/Quote - 2. Installation/Service. Worksheets: Implement standard Odoo Worksheets for our engineers to fill out on-site via their mobile devices. Timesheets & Trainees: Implement Timesheets for our 3 lead engineers. Crucial: Our trainees will not have Odoo logins. We need a simple, frictionless workaround (e.g., a free web form via Zapier, or leads logging crew time) so their hours still end up allocated to the correct Odoo project/job. Milestone 3: Serialised Inventory & Fleet Management Inventory Tracking: Configure the Inventory app to track high-value units (Air Conditioning units, Boilers) strictly by Serial Numbers for warranty and service tracking. Fleet Management: Set up the Fleet module to track our company vans, MOTs, services, and assignments to engineers. Milestone 4: Subscriptions, Marketing & Communications Annual Servicing: Set up the Subscriptions module to automatically manage and bill for annual boiler or AC servicing agreements. Marketing: Configure Marketing Automation and Email Marketing for customer retention and follow-ups. WhatsApp & SMS: Integrate standard Odoo WhatsApp messaging and ClickSend (via Zapier) for automated customer appointment reminders and updates. Milestone 5: Future-Proofing Advise and prepare the Odoo backend/API for a future phase where we will connect a headless website system. Required Skills: Deep, proven expertise in standard Odoo Online v19 apps (CRM, Sales, Purchase, Inventory, Field Service, Subscriptions, Marketing). Strong understanding of Odoo's Inventory Routing (Make to Order, Kits/BoMs, Dropshipping). Zapier automation skills. Ability to map complex business processes into standard Odoo without resorting to custom code.