Each part exists in its own coordinate system in the Part module, and you use the Assembly module to position and orient instances of these parts relative to each other in a global coordinate system. ABAQUS/CAE provides the following tools for positioning part instances:
Auto-offset
When you create the first part instance in the Assembly module, ABAQUS/CAE displays a triad indicating the origin and the orientation of the global coordinate system. ABAQUS/CAE positions the first part instance so that the origin of the part aligns with the origin of the global coordinate system and the axes are aligned. If you create additional part instances, ABAQUS/CAE continues to position the new instances such that their coordinate system aligns with the global coordinate system. Since this usually results in new part instances overlapping existing ones, ABAQUS/CAE allows you to apply an offset before it creates the instance. The offset is applied along the X-axis for three-dimensional and two-dimensional part instances and along the Y-axis for axisymmetric part instances.
Basic positioning tools
ABAQUS/CAE provides the following basic methods for positioning part instances:
You can translate selected part instances along a vector by specifying the coordinates of the start point and end point of the translation vector. You can use the following methods to determine the distance moved by the selected part instances:
The selected part instances move along the translation vector from the start point to the end point.
The selected part instances move along the translation vector from the start point toward the end point and continue to move until a selected face or edge is a specified distance from a face or edge selected from the fixed part instances. For more information, see “Positioning a part instance using the Translate To tool,” Section 13.4.4.
You can rotate selected part instances about an axis. You specify the X-, Y-, and Z-coordinates of the start point and end point of the axis of rotation and the angle of rotation.
Position constraint tools
A position constraint defines a relationship between two part instances. Unlike a simple translation or rotation, you do not specify the position directly. Position constraints define a set of rules that must always be met by the part instances in the assembly; for example, a face that must be parallel to another face.
Position constraints defined in the Assembly module define constraints only on the initial positions of instances, whereas constraints defined in the Interaction module define constraints on the analysis degrees of freedom. In the Assembly module constraints are stored as features of the assembly. If you modify a part or move a part instance, ABAQUS/CAE attempts to apply all existing position constraints when it regenerates the assembly. Each of the position constraints is described in “How the position constraint methods differ,” Section 13.4.2.
Creating the final assembly is an iterative process of creating part instances, applying position constraints, and applying translations and rotations. After each repositioning, ABAQUS/CAE displays a temporary image indicating the result of the operation. You can accept the new position, cancel the operation, or step back through the repositioning procedure by clicking the Previous button 
in the prompt area.
You can use the Query toolset to obtain the coordinates of a vertex and to measure the distance between selected vertices. This may help you determine the vector along which you need to translate part instances or the angle through which you need to rotate them. “Using the Query toolset to query the assembly,” Section 13.11, contains detailed instructions on how to obtain information about the assembly.