Commitments and contingencies (Tables)

12 Months Ended

Dec. 31, 2015

Commitments and contingencies

Schedule of environmental obligations included in other current provisions and other noncurrent provisions

	December 31,
($ in millions)	2015		2014
Other provisions		30		37
Other non-current liabilities		86		109
Total		116		146

Best estimate of future payments for guarantee obligations

	December 31,
	2015		2014
($ in millions)	Maximum potential payments
Performance guarantees		209		232
Financial guarantees		77		72
Indemnification guarantees		50		50
Total		336		354

Provisions for warranties

($ in millions)	2015			2014
Balance at January 1,		1,148			1,362
Net change in warranties due to acquisitions and divestments		—			11
Claims paid in cash or in kind		(281	)		(319	)
Net increase in provision for changes in estimates, warranties issued and warranties expired		301			224
Exchange rate differences		(79	)		(130	)
Balance at December 31,		1,089			1,148