I. INTRODUCTION  
II. PROBLEM DESCRIPTION AND NOTATION  
III. HEURISTIC METHODS FOR THE UNRELATED MACHINES ENVIRONMENT  
A. Problem specific heuristics  
B. Meta heuristics  
IV. CLASSIFICATION OF RESEARCH  
V. RECENT TRENDS AND FUTURE DIRECTIONS  
A. Problem definitions  
B. Solution methods  
C. Dynamic and stochastic problems  
D. Application for real world problems  
E. Green scheduling  
VI. CONCLUSION