These terms originate from the "buy-class" framework, which categorises organisational purchasing. A 'new buy' (or new task) is the most complex situation because the organisation has no prior experience with the purchase, requiring a full problem-solving process. A 'modified re-buy' is less complex; the buyer has some experience but seeks changes, prompting a limited problem-solving effort to evaluate alternatives. This falls between a 'new buy' and a 'straight re-buy' (a routine repurchase with no changes), which requires minimal decision-making.

1. Robinson

P. J.

Faris

C. W.

& Wind

Y. (1967). Industrial buying and creative marketing. Allyn & Bacon. This is the seminal work that introduced the buy-class framework

defining new buy

modified re-buy

and straight re-buy as the three primary types of industrial buying situations. The framework is detailed in Chapter 2.

2. Kotler

P.

& Keller

K. L. (2016). Marketing Management (15th ed.). Pearson Education. In Chapter 7

"Analyzing Business Markets

" the text defines the three buy-classes. It describes a new task as a situation where "the purchaser buys a product or service for the first time" and a modified rebuy where "the buyer wants to change product specifications

prices

delivery requirements

or other terms."

3. Johnston

W. J.

& Lewin

J. E. (1996). Organizational buying behavior: Toward an integrative framework. Journal of Business Research

35(1)

1–15. This academic review discusses the buygrid model

defining the new task as having the greatest uncertainty and the modified rebuy as an intermediate situation where buyers may seek new suppliers for better quality or prices (p. 3). DOI: https://doi.org/10.1016/0148-2963(94)00077-B00077-B)

4. Webster

F. E.

& Wind

Y. (1972). A General Model for Understanding Organizational Buying Behavior. Journal of Marketing

36(2)

12–19. This foundational article elaborates on the buying situations

explaining that the complexity of the buying process and the information needs of the organization vary significantly across the new-task

modified-rebuy

and straight-rebuy situations (p. 14). DOI: https://doi.org/10.2307/1250972