Glossary entry (derived from question below)
Portuguese term or phrase:
prestações
English translation:
deliverables
Portuguese term
Translations by lawyers for lawyers
Native in: English 
Works in: Portuguese to English, English
prestações
This text above appears in a public procurement and contracting code, which I am translation.
"prestações que constituem o objeto do contrato a celebrar" clearly does not refer to all obligations under the contract, but only to the obligations comprised in the supply of the goods, services, or works contracted. This is clear because if these "prestações" are simple in technical terms, the tender specifications are reduced to technical specifications and mere reference to other essential aspects.
None of the entries in the ProZ terminology resources is appropriate. Undifferentiated answers like performance and obligations will not suffice, for the reasons stated above.
Proposed translations
Brazil
Translates IT, Apps Tutorials & Mining
Native in: Portuguese 
Works in: English to Portuguese, Portuguese to English, Spanish to Portuguese, and 3 more.
deliverables
| Muito bem! |
| agree |
Arthur Sayeg
: Agreed.
2 hrs
|
|
Obrigado, Arthur.
|
|
| agree |
Mario Freitas
:
9 hrs
|
|
Obrigado, Mario.
|
Brazil
Marketing, Sustainability, Finance
Native in: Portuguese (Variant: Brazilian)
Works in: English to Portuguese, Portuguese to English
services
| Nem todas as obrigações contratuais dizem respeito ao objecto do contrato, ex. g. obrigações relativas à confidencialidade, alteração de endereço para as notificações, arbitragem, etc. |
| Desculpe Patrícia. Está resposta não era para si. |
Brazil
Trilingual translator and proofreader
Native in: Portuguese (Variant: Brazilian)
Works in: English to Portuguese, Portuguese to English, Japanese to Portuguese, and 3 more.
contractual obligations
| Nem todas as obrigações contratuais dizem respeito ao objecto do contrato, ex. g. obrigações relativas à confidencialidade, alteração de endereço para as notificações, arbitragem, etc. |
Austria
Retd.T&I, Barrister & Austro-Advokat
Native in: English (Variants: British, Scottish)
Works in: Spanish to English, English to Spanish, French to English, and 5 more.
core-requirements (desiderata)
Schedule of Requirement (SOR) cum Offer Form for Tender No. xxx
http://www.collinsdictionary.com/dictionary/english/desiderata
http://www.proz.com/kudoz/spanish-to-english/law-general/3605057-prestación-accesoria.html
| Nice one. I might prefer core obligations. |
Brazil
32 years engineering/law/contracts
Native in: English (Variant: US) , Portuguese (Variant: Brazilian)
Works in: English to Portuguese, Portuguese to English
contractual performance
But when it refers to the contractor's obligations, then this is my suggestion.
Brazil
Legal, Technical, TI, medical
Native in: Portuguese
Works in: Spanish to Portuguese, Portuguese to Spanish, English to Portuguese, and 6 more.
Discussion
Adrian e Paulinho propuseram respostas válidas que resolvem o problema. A resposta do Paulinho tem a vantagem de limitar-se às prestações do contratante privado, enquanto a resposta do Adrian aplica-se tantos às prestações do contratante privado como às do contratante público.
Assim, irei adotar a sugestão do Paulinho (deliverables) na tradução de prestação do contratante privado, e a sugestão do Adrian (core requirements/obligations) na tradução de prestações do contratante público.