The activity relationship chart (ARC) is a tabular means of displaying the closeness rating among all pairs of activities or departments.. In an ARC, there are six closeness ratings that can be assigned to each pair of departments, as well as nine reasons for those ratings (each is assigned by a reason code).

Rating symbols

• A: Absolutely Necessary
• E: Especially important
• I: Important
• O: Ordinary closeness
• U: Unimportant
• X: Undesirable

Reason Codes

1. )Same table
2. )Flow of material
3. )Service
4. )Convenience
5. )Inventory control
6. )Communication
7. )Same personnel
8. )Cleanliness
   Cleanliness
   Cleanliness is both the abstract state of being clean and free from dirt, and the process of achieving and maintaining that state.Cleanliness may be endowed with a moral quality, as indicated by the aphorism "cleanliness is next to godliness," and may be regarded as contributing to other ideals...
   
   
9. )Flow of parts

A thumb rule has been in use to restrict the choice of rating letters:

• Very few A and X relationships should be assigned. (No more than 5%).
• No more than 10% should be an E.
• No more than 15% to be an I.
• No more than 20% to be an O.
• About 50% of the relationships should be U.

Developing an activity relationship chart

1. List down all the departments that are within the facility (Draw a rectangle with a pointy edge around each one of them).
2. Draw a rhombus
   Rhombus
   In Euclidean geometry, a rhombus or rhomb is a convex quadrilateral whose four sides all have the same length. The rhombus is often called a diamond, after the diamonds suit in playing cards, or a lozenge, though the latter sometimes refers specifically to a rhombus with a 45° angle.Every...
   
   between each department until you fully construct the rhombus as tree.
3. Split every rhombus into two halves. (The upper half is for the rating letter, while the lower half is for the rating reason code)