A will was left but there was no witnesses, the immediate family didn't get the house and business owned by the deceased, the workers got it, California.

Do you mean, not necessarily witnesses, but no family members were named in the will. To make it perfectly clear what probate means, here is the legal explanation from anz.com



Probate

The hearing and determining of any queries about entitlements under the terms of a will. The executor of a will has to obtain the probate document (certificate) from the court to enable him or her to carry out the instructions contained in the will. A deceased person's estate or wealth described as 'subject to probate' is frozen pending the issuing of the probate certificate which confirms that the will is valid and can be executed. Probate comes from the Latin probatus meaning 'proved'.

Unless there was a will, or unless the workers were part owners,
The owners can not just take over, probate would appoint someone to manage it till it is given out in court

Thanks for the responses, there were no witnesses on the written document and thus only the wishes delineated by the deceased (who gets what) and signature. It specifies monies in accounts, cars, house, the business, to specific people with varying amounts of money. The only question is whether witnesses needed to be on the document and their signatures. The executor is not specifically named.