Supply chain rationalisation is the strategic process of reorganizing a supply chain to improve its efficiency, effectiveness, and cost-performance, typically through simplification and reduction. Reducing the number of suppliers, also known as supply base rationalisation, is a core tactic. It consolidates purchasing power, reduces administrative overhead, and fosters stronger, more strategic relationships with remaining suppliers. Tier-skipping is another rationalisation tactic where a company bypasses an immediate tier in its supply chain (e.g., a distributor or Tier 1 supplier) to deal directly with a lower-level supplier (e.g., a Tier 2 component manufacturer). This simplifies the supply chain structure, reduces costs by eliminating intermediary markups, and can improve communication and control.

A. Customisation: This involves tailoring products to specific customer needs, which typically increases complexity and costs, contradicting the simplification goal of rationalisation.

B. Supplier innovation: This is a value-creation strategy focused on leveraging supplier expertise for new ideas, not a method for streamlining or reducing existing supply chain complexity.

C. Collaborative inventory management: This is a partnership-based operational strategy (like VMI) to optimise stock levels, rather than a structural simplification of the supply base or chain tiers.

1. Ogden, J. A. (2006). Supply base reduction: an empirical study of critical success factors. Journal of Supply Chain Management, 42(4), 29-39. This paper defines and analyses supply base reduction (reducing the number of suppliers) as a key strategic purchasing initiative aimed at improving efficiency and performance. (DOI: https://doi.org/10.1111/j.1745-493X.2006.00019.x)

2. Christopher, M. (2016). Logistics & Supply Chain Management (5th ed.). Pearson. In Chapter 3, Christopher discusses the principle of simplification and reducing complexity as fundamental to creating lean and agile supply chains, highlighting that "often the number of suppliers can be significantly reduced" as part of this process (p. 78).

3. Trent, R. J., & Monczka, R. M. (2003). Understanding integrated global sourcing. International Journal of Physical Distribution & Logistics Management, 33(7), 607-629. The authors discuss sourcing strategies that involve rationalising the supply base and establishing direct relationships with producers, which aligns with both reducing suppliers and the principle behind tier-skipping (disintermediation) to simplify the chain (p. 618). (DOI: https://doi.org/10.1108/09600030310499286)