Let us first compare some of the features and characteristics of each type of organization.

Mechanistic Organizations:

High Specialization
Rigid Departmentalization
Clear Chains of command
Narrow Spans of Control
Highly centralized
Highly formalized
Bureaucracy
Well-oiled machine

Organic Organizations:

Cross-Functional Teams
Cross Hierarchical Teams
Free Flow of information
Wide Spans of Control
Decentralized
Low Formalization
Adhocracy
Adaptable Amoeba

source: http://www.csun.edu/~dmz51283/360-S06/In-class%20PPTs/21

In recent times, the trend is more towards organic organizations due to the fact that today's dynamic and fast business environment requires organization to be more flexible and easily adaptable to changing dynamics of the business environment. Further, there is a greater need to empower the employees which is more possible in organic organizations.

The mechanistic design is highly centralized, formalized and standardized, leaving little discretion to individual employees. It resembles a machine and represents order, control and consistency. An organic design is decentralized, loose, with little or no documentation and standardization.

The mechanistic design is more prevalent when technology is well understood, markets are predictable, and the organization is large. An organic design is more likely when technology is poorly understood, markets are volatile or the organization is small.

Thus, based on the above mentioned characteristics, we can say that organic organizations are more suitable for small organizations where flexibility is the key and formal structure is not suggested as the small size of the organization requires close cooperation among the employees.

Similarly, mechanistic organization will be more valuable and useful in large organization, which cannot afford to appear messy and chaotic and cannot leave decision making to individual employees. It is absolutely necessary in situations where control is necessary and formal structures are required.

Organic organizations work well in scenarios where each employee is expected to contribute to common tasks and teamwork and cooperation to complete each task is highly desirable. Mechanistic organizations will be necessary if strict hierarchy of authority and control need to be implemented.

source: http://www.unc.edu/~nielsen/soci110/nm4/e3-6.gif

source: http://www-management.wharton.upenn.edu/pennings/coursedocuments/executive_education_courses/555/WAMAYC555Winter.doc.

2. Organizational goals are important, where do they originate? Also, what is the possible impact goals may have on an organization and its activities.

Organizational goals are extremely important in the sense that they provide a sense of direction to the efforts of the organization and helps in binding the tasks of the organization together and basically provides a reason for the existence of the organization. Such goals originate during the strategic planning stage, especially the strategy formulation stage when the management formulates the mission, vision, goals and objectives for the entire organization.

In the absence of such goals, be it short, medium or long term, there will be complete chaos and mess in the organization as there will be clear direction for the organization to move forward. As soon as the organizational goals are defined during the strategy formulation stage, other important decisions start taking shape in the light of overall organizational goals. Thus, organizational goals does the act of binding the act of the organization together.