The concern of consumers about unnecessary packaging is an external factor that influences the organisation. The appropriate technique for systematically analysing these external macro-environmental factors is PESTLE analysis. PESTLE stands for Political, Economic, Sociological, Technological, Legal, and Environmental factors. The increasing consumer concern about packaging falls clearly under the Sociological or Environmental categories of the PESTLE framework. This technique helps the business analyst identify trends and issues arising from outside the organisation that may create a business need or risk, which then drives strategic change. The other options are incorrect: a Power/Interest grid is for stakeholder management; Boston Box (BCG Matrix) is for product portfolio management; and a Resource Audit is for internal analysis of resources.

(Reference: BCS Foundation Certificate in Business Analysis / BCS Business Analysis Practice – Strategic Analysis, External Environment Analysis)