An increasing or decreasing patterns of demand over time is considered as a:

A trend is the fundamental component of a time series that represents the long-term, sustained upward or downward movement of data over a significant period. It captures the underlying direction of the series, abstracting away from shorter-term fluctuations. This definition precisely matches the question's description of "an increasing or decreasing patterns of demand over time." In demand forecasting, identifying the trend is a critical first step in understanding long-range demand behavior.

B. Cycle: Refers to wavelike, non-seasonal fluctuations that last longer than one year, often influenced by macroeconomic conditions, not a simple long-term directional movement.

C. Seasonality: Describes predictable, repetitive patterns that occur at regular intervals within a one-year period (e.g., monthly or quarterly), not a continuous increase or decrease.

D. Analysis: Is the process of examining data to uncover patterns like trends; it is not the pattern itself.

1. Hyndman

R. J.

& Athanasopoulos

G. (2018). Forecasting: Principles and practice (2nd ed.). OTexts. In Chapter 6.1

"Time series components

" a trend is defined as existing "when there is a long-term increase or decrease in the data." https://otexts.com/fpp2/components.html

2. MIT OpenCourseWare. (2016). 15.762 Supply Chain Planning

Lecture 3: Introduction to Forecasting. Massachusetts Institute of Technology. The lecture notes explicitly define a trend as a "long term movement of the mean" and distinguish it from seasonality (periodic fluctuations) and cycles (long-term economic fluctuations). https://ocw.mit.edu/courses/15-762-supply-chain-planning-spring-2016/resources/mit15762s16lec3/

3. Makridakis

S.

Wheelwright

S. C.

& Hyndman

R. J. (1998). Forecasting: Methods and Applications (3rd ed.). John Wiley & Sons. Chapter 2 discusses time series decomposition

defining a trend (T) as the long-term change in the level of the data. (This is a foundational academic text in forecasting).