As an asset class, property is already difficult to appraise and forecast. Much more so if we are talking about shopping centres, where agglomeration, variety, quality of tenants and brands add to the complexity. Tenant mix is a “puzzle” in shopping centre management. The reason is because tenant mix seems to be an art, the art of marketing. A typical shopping centre contains more than 100 retail units – thus the possible tenant mix arrangements of retail/service categories and brands are almost infinite. Moreover, tenant mix is not a static condition: the market changes over time, as do customer preferences and fashion trends. Consequently, centre managers have to adjust their tenant mix constantly to keep up with market trends and will therefore need to move tenants around, negotiate lease renewals, lease reviews or even actively break leases so to improve shopping centre productivity.