Concrete Mix design......

Fresh concrete is in mouldable condition to do the concreting properly without honey comb or crack.

Workability

The workability covers the following properties,
Mobility
Compactibility
Finishability
Pumpability

These concrete properties will varies for given construction situation/ Elements.

Workability Test Methods

There are various tests are available to compute the workability,  but the common method is SLUMP TEST. 

The Vebe test and Tattersall 2 point test are may be used in research laboratories.  but they are rarely used in the field.

There are two reason to specifying a Workability test method for fresh concrete,

1. Control of workability within a range to the construction condition , transporting equipment , placing
    equipment and compacting method.

2. Control of the water content (Indirectly )
    ie; (water /cement) ratio