Sales funnels and customer pipelines with Mermaid diagrams

Sales teams live by the funnel—leads enter at the top, some convert to customers, others fall out. But funnels are easy to imagine and hard to visualize when they actually matter: during pipeline reviews, win/loss retrospectives, and when onboarding reps who ask "where do deals typically stall?" A diagram showing the funnel's structure, drop-off points, and conversion gates gives teams a shared language and helps managers spot where to coach or improve process.

Anatomy of a sales funnel

A sales funnel has stages (Awareness → Interest → Evaluation → Purchase) and flows (deals move forward or churn out). Each stage has a conversion rate (what % move to the next); the funnel narrows as a result. Mermaid flowcharts or Sankey diagrams model this elegantly.

Flowchart approach → emphasizes decision logic ("did they respond?", "is budget approved?")
Sankey approach → emphasizes flow and volume ("100 leads → 30 qualified → 8 proposals → 2 closed")

Simple sales funnel: B2B SaaS

flowchart TD
    A([Inbound Lead])
    B["Send intro email"]
    C{Opens email?}
    D{Responds?}
    E["Schedule call"]
    F{Qualified<br/>budget & need?}
    G["Send proposal"]
    H{Review<br/>proposal?}
    I["Negotiate terms"]
    J{Decision<br/>maker<br/>approves?}
    K([Customer])
    L([Lost - No response])
    M([Lost - Not qualified])
    N([Lost - No decision])
    
    A --> B --> C
    C -->|No| L
    C -->|Yes| D
    D -->|No| L
    D -->|Yes| E --> F
    F -->|No| M
    F -->|Yes| G --> H
    H -->|No| M
    H -->|Yes| I --> J
    J -->|No| N
    J -->|Yes| K
    
    style K fill:#d4f1d4
    style L fill:#f1d4d4
    style M fill:#f1d4d4
    style N fill:#f1d4d4

This diagram shows:

• Decision gates at each stage (email open, response, qualification, proposal review, approval)
• Loss paths (where deals exit—lack of response, budget, or buy-in)
• Win path (the journey to closed-won)
• Stage clarity (Awareness → Interest → Evaluation → Negotiation → Close)

Each colored path represents an outcome; managers can track where their deal volume typically leaks.

Funnel with rework loops: more realistic

Real sales isn't linear. A prospect might go silent, then re-engage months later. A deal might be "Evaluation" for 6 months (stuck with a committee). Teams often loop back to proposal after feedback.

flowchart TD
    A([Inbound])
    B["Initial call"]
    C{Engagement<br/>level?}
    D["Send case study"]
    E["Wait 1 week"]
    F{Re-engagement?}
    G["Deep-dive demo"]
    H{Technical<br/>fit?}
    I{Budget<br/>approved?}
    J["Send proposal"]
    K{Decision?}
    L["Address<br/>objections"]
    M([Closed-Won])
    N([Dormant - Revisit later])
    O([Lost])
    
    A --> B --> C
    C -->|Low| D --> E --> F
    F -->|No| N
    F -->|Yes| G
    C -->|High| G
    G --> H
    H -->|No| L --> L
    H -->|Yes| I
    I -->|No| L
    I -->|Yes| J --> K
    K -->|Yes| M
    K -->|No| L
    L -->|Convinced| J
    L -->|Give up| O
    
    style M fill:#d4f1d4
    style N fill:#fff5d4
    style O fill:#f1d4d4

Key features:

• Engagement check early (if low, nurture loop; if high, jump to demo)
• Rework loop (L → J) for objection handling
• Dormant state (not a loss, but parked for later)
• Time gates (1-week wait before re-engaging cold leads)

Sales funnel with team handoffs

Different roles own different stages. SDRs own Awareness/Interest; AEs own Evaluation/Negotiation; CSM owns onboarding. Show who owns what:

flowchart TD
    subgraph SDR["SDR (Business Development)"]
        A([Lead])</
        B["Qualify lead<br/>firmographic match"]
        C["Send cold email"]
        D{Response?}
    end
    
    subgraph AE["Account Executive"]
        E["Schedule call"]
        F["Product demo"]
        G{Evaluation<br/>passed?}
        H["Send proposal"]
        I{Win/Loss<br/>decision?}
    end
    
    subgraph CSM["Customer Success"]
        J["Onboard customer"]
        K["Confirm success<br/>metrics"]
    end
    
    L([Lost - SDR Stage])
    M([Lost - AE Stage])
    N([Customer])
    
    A --> B --> C --> D
    D -->|No| L
    D -->|Yes| E
    E --> F --> G
    G -->|No| M
    G -->|Yes| H --> I
    I -->|No| M
    I -->|Yes| J --> K --> N
    
    style N fill:#d4f1d4

This diagram makes visible:

• Role boundaries (where one person hands off to another)
• Churn by stage (SDR loses some; AE loses some)
• Handoff risk (between SDR → AE is a common drop-off point)

Funnel metrics: flow volume (Sankey)

Flowcharts show logic; Sankey diagrams show scale. If 1000 inbound leads arrive but only 50 close, a Sankey reveals where the volume drains:

sankey-beta

Leads,Qualified,500
Leads,Not Qualified,500

Qualified,Proposal Sent,300
Qualified,No Response,200

Proposal Sent,Won,50
Proposal Sent,Lost,250

Won,Customer,50

Reading this Sankey:

• 50% of inbound are actually qualified (1000 → 500)
• Of qualified, 60% get proposals (300/500)
• Of proposals, only 17% close (50/300) — this is the leak
• 50 customers from 1000 inbound = 5% conversion funnel (healthy for B2B SaaS)

Use this to set metrics and coach the team: "Our win rate on proposals is 17%. If we improve it to 25%, we add 60 more deals/year."

Funnel by deal size or segment

Complex sales often have different paths for different deal sizes:

flowchart TD
    A([New Lead])
    B{Deal size<br/>estimate?}
    
    C["Nurture email<br/>sequence"]
    D["Self-serve<br/>trial"]
    E{Converted?}
    F([Mid-market<br/>lead pool])
    
    G["Enterprise<br/>sales motion"]
    H["Executive<br/>intro"]
    I{CIO interest?}
    J["3-month POC"]
    K{ROI case<br/>proven?}
    L([Enterprise<br/>customer])
    
    M([Lost])
    
    A --> B
    B -->|<$5k| C
    B -->|$5-50k| F
    B -->|>$50k| G
    
    C --> D --> E
    E -->|No| M
    E -->|Yes| F
    
    F --> G
    G --> H --> I
    I -->|No| M
    I -->|Yes| J --> K
    K -->|No| M
    K -->|Yes| L
    
    style L fill:#d4f1d4
    style M fill:#f1d4d4

This shows:

• Self-serve path for smaller deals (quick conversion or churn)
• Sales-assisted path for mid-market (email nurture)
• Enterprise path for large deals (executive intro, POC, ROI case building)

Each path has different timelines, stages, and criteria. Reps need to know which path applies to their lead.

Win/loss analysis: where did we fail?

After-the-fact analysis: diagram your actual won and lost deals over the past quarter to identify patterns:

flowchart LR
    A([Deal])
    B{Qualified?}
    C{Had<br/>budget?}
    D{Had<br/>compelling<br/>event?}
    E{Had<br/>decision<br/>maker<br/>access?}
    
    F([Won])
    G([Lost:<br/>Not qualified])
    H([Lost:<br/>Budget<br/>deferred])
    I([Lost:<br/>No urgency])
    J([Lost:<br/>No<br/>buy-in])
    
    A --> B
    B -->|No| G
    B -->|Yes| C
    C -->|No| H
    C -->|Yes| D
    D -->|No| I
    D -->|Yes| E
    E -->|No| J
    E -->|Yes| F
    
    style F fill:#d4f1d4
    style G fill:#f1d4d4
    style H fill:#f1d4d4
    style I fill:#f1d4d4
    style J fill:#f1d4d4

After mapping 20 recent losses, if most fail at the "compelling event" gate, you know the problem: prospects don't see urgency. Coach reps to uncover pain sooner or ask "what would make this a priority?"

Funnel metrics to track

Metric	Formula	Example
Conversion rate, Awareness → Interest	Responses / Outreach	20 responses / 500 emails = 4%
Conversion rate, Interest → Evaluation	Demos / Qualified leads	15 demos / 30 qualified = 50%
Conversion rate, Evaluation → Proposal	Proposals / Demos	12 proposals / 15 demos = 80%
Win rate (Proposal → Close)	Won / Proposals	2 won / 12 proposals = 17%
Average deal cycle (time in funnel)	Days from first touch to close	Awareness → Close = 45 days average
Churn by stage	Deals exiting at each stage	40% churn at "response" gate

Track these monthly. If win rate drops from 25% to 15%, investigate: did process change? Did customer segment shift? Did competitor new feature ship?

Best practices for funnel diagrams

1. Keep stages to 4–6 — more than 6 is hard to visualize and usually means you're over-processing
2. Label gates with criteria — "Budget approved" is clearer than "Gate"
3. Show velocity, not just logic — use Sankey when volume matters, flowchart when decision logic matters
4. Update quarterly — funnels shift with market, product changes, and team skill
5. Color outcomes — green for won, red for lost, yellow for dormant
6. Run retrospectives from the diagram — "Why do 40% fall out here? What can we improve?"

FAQ

Should my funnel match the standard marketing funnel (Awareness, Interest, Decision, Action)?
Not necessarily. Use the stages your sales process actually has. A fast-sales SMB tool might have 3 stages (Outreach, Trial, Close); an enterprise software company might have 6+ (Inbound, Qual, Discovery, Proposal, Negotiation, Close). Your stages should match your process.

How often should I redraw the funnel?
Quarterly, or when process changes (hiring new AEs, launching new product, entering new market). The diagram is your source of truth for training and process improvement.

Can I show multiple funnels for different products?
Yes. Draw separate diagrams for each product line or market segment—this reveals where one product converts better, or where one segment stalls.

How do I forecast revenue from a funnel?
Multiply the number of deals in each stage by their average deal size, then by the stage conversion rate to the next stage. E.g., 20 proposals × $15k average deal × 17% win rate = $51k expected closed deals.

Build your sales funnel in MermaidCreator and share it with your team to align on where deals stall and where to focus coaching.