Types of Commercial Relationships in Supply Chains
SRM (Supplier Relationship Management) is the process of identifying all interactions with key suppliers and managing them so that value increases for both parties. AC 1.1. There is no single "best" relationship type — the right choice depends on the category, risk profile, and market conditions.
Internal vs external supply
The first choice is whether to make or buy.
Internal supply (in-house) typically produces core products or services and is governed by the make-or-buy decision.
- Advantages: greater control, continuity of supply, quality oversight, lower cost (no supplier margin), protected IP.
- Disadvantages: no competitive pressure to improve unless benchmarked; the organisation carries fixed and variable costs (an external supplier carries only variable cost); investment carries an opportunity cost. Internal supply may not work where volumes are too low, licences or permits are required, or key skills are scarce.
External supply (independent supplier) brings market expertise and scale. Selection weighs purchase price, delivery lead time, quality and experience; risks to evaluate include insolvency, delays, natural disasters, human-rights issues and political instability.
- Advantages: specialist knowledge, economies of scale, frees internal resources, flexibility to demand swings.
- Disadvantages: dependency risk (insolvency, disruption, political instability), reputational risk from unethical supplier behaviour, transport and management cost.
The relationship spectrum
The spectrum classifies the relationship currently in place, running from competitive/tactical (left) to collaborative/strategic (right). Moving right, trust, duration, communication depth, and innovation all increase together.
| Type | Character |
|---|---|
| Adversarial | Deal outcome over relationship; non-core or one-off; low trust, short-term contracts |
| Arm's-length | Infrequent; parties act independently, exploiting market pricing |
| Transactional | Higher frequency/volume; low value, low risk; competitive tendering viable |
| Closer tactical | Competent supplier needed but full collaboration not commercially justified |
| Single-source | One chosen supplier for commercial benefit (e.g. volume discounts); top-management decision; high trust and dependence |
| Outsourced | In-house activity moved out for cost or capability reasons; TUPE applies to transferring staff |
| Strategic alliance | Independent organisations pursue agreed objectives, each retaining a separate legal identity |
| Partnership | High-risk/high-value; long-term; broadly equal power; focus on innovation and quality improvement |
| Co-destiny | Deep interdependence; buyer and supplier make decisions jointly; the most collaborative position |
Exam trap: the spectrum classifies the current relationship, not the ideal one. Exam questions often describe a scenario and ask where it sits on the spectrum, or what change is needed and why. Know what drives movement right (greater trust, longer duration, deeper communication, joint innovation) versus what justifies staying left (low risk, low value, plentiful alternatives).
The relationship life cycle
Relationships evolve through stages: on-boarding → qualification → segmentation → risk management → performance management → development and innovation → phase-out (if required).
At qualification, buyers use RFI/RFP and may apply Carter's 10 Cs: Competency, Capacity, Commitment to quality, Control of processes, Cash, Cost, Consistency, Culture, Clean, Communication. Thorough, but time- and resource-intensive for both parties.
At performance management, KPIs typically span: Safety (injury frequency), Quality (stock accuracy, shrinkage, obsolescence), Delivery (in-full-on-time, defects), Cost (to budget, continuous improvement targets, waste), Morale (attendance, survey results), and Environment (waste to landfill, CO₂ emissions).
Supplier development — working with a supplier to improve its processes or products — addresses previous performance issues, lifts performance, or has the supplier adopt the buyer's technologies or help develop new products and services. Done well, it produces mutual benefit: reduced cost, less supply-chain waste, and the long-term security that increases a supplier's motivation and innovation. It is applied selectively, where supply risk, strategic importance, supplier potential, switching options, performance gap, willingness, and expected return all justify the investment. For the methods and tools, see the Supplier Development Techniques page.
Resolving conflict
Conflict between buyer and supplier resolves three ways: win-lose (one party gains at the other's expense), lose-lose (neither achieves what it needs), or win-win — a position beneficial to both parties, and the collaborative target in strategic relationships.
Key terms
- SRM — managing all interactions with key suppliers to increase value for both parties.
- Relationship spectrum — continuum from adversarial (competitive) to co-destiny (collaborative); nine positions.
- Single-source — deliberate choice of one supplier for commercial benefit; higher trust and dependence than multi-source.
- Outsourcing — transferring an internal activity to an external supplier; TUPE applies when staff transfer.
- Strategic alliance — independent organisations collaborating on agreed objectives, each retaining separate legal identity.
- Co-destiny — deepest collaborative position; joint decision-making with high mutual interdependence.
- Carter's 10 Cs — supplier qualification framework: Competency, Capacity, Commitment to quality, Control of processes, Cash, Cost, Consistency, Culture, Clean, Communication.
- Win-win — conflict outcome where both parties benefit; the target in collaborative relationships.
- TUPE — Transfer of Undertakings (Protection of Employment) Regulations; protects employee terms when work transfers to a new employer.
Sources: CIPS L4M6 Study Guide; Carter's 10 Cs of supplier evaluation (developed from Carter, 1995).